Compositions for sialic acid sensing, cancer cell imaging and methods of use thereof

Abstract

Disclosed are compounds, particularly compounds capable of sensing and / or imaging glycans (such as sialic acid, etc., such as mono-sialic acid, di-sialic acid, tri-sialic acid, polysialic acid) and / or cancer cells and capable of distinguishing between cancer cells and normal cells. The compound is a d8 or d10 metal complex or a salt thereof. The metal complexes may bind to glycans (such as, for example, monosialic acid, disialic acid, trisialic acid, and polysialic acid, etc.) and / or cancer cells. The combination interaction induces the accumulation of the metal complex and the self-assembly of the supramolecules, thereby causing the change of the photophysical properties of the metal complex.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 63 / 620,355, filed on January 12, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention pertains to the fields of early diagnosis and imaging - guided therapy, particularly for detecting and / or sensing analytes, especially glycans (such as sialic acids (e.g., monosialic acid, disialic acid, trisialic acid, etc.) and polysialic acid, etc.); and / or detecting and / or sensing cancer cells, as well as visualizing and monitoring glycans (such as sialic acid and polysialic acid, etc.) in biological samples and differentiating cancer cells from normal cells. Background Art

[0004] All eukaryotic cells are covered with a dense and complex glycan layer. Glycans play crucial roles in regulating many cellular physiological and pathological processes, including cell trafficking and signal transduction, which transmit information between cells in the form of glycoproteins and glycolipids (Dube et al., Nat. Rev. Drug Discov., 4, 477 - 488 (2005)). Glycans have structural diversity, with each glycan having a unique structure and different types of monosaccharide sequences (Laughlin et al., Proc. Natl. Acad. Sci. U.S.A., 106(1), 12 - 17 (2009)). Sialic acids share a nine - carbon backbone and are typically located at the termini of glycan chains on the cell surface (Schauer et al., Glycoconj. J., 17, 485 - 499 (2000)). Sialic acids regulate various biological processes, contributing to signal transduction and immune responses. An interesting physiological role of sialic acids is to transmit an "self" signal to immune cells, enabling the cells to escape attack by the immune system. The increase in sialic acid levels in many cancer cells has important implications in acting as a biological mask to evade immune system recognition and promoting metastatic spread (Narayanan et al., Ann. Clin. Lab. Sci., 24(4), 376 - 384 (1994)). Overexpressed sialic acids can be used as biomarkers for cancer. Therefore, developing sensitive and selective sensors for detecting sialic acid, polysialic acid, glycans, and cancer cells is very important in early diagnosis and treatment guidance.

[0005] Quantitative methods for glycans (such as sialic acid, polysialic acid, etc.) in samples (preferably biological samples such as serum or plasma, etc.) have been established to facilitate the exploration of further mechanisms related to psychological and pathological processes and early diagnosis. Commonly used methods include high-performance liquid chromatography (HPLC), mass spectrometry (MS), and colorimetric assays (Zhou et al., Cells, 9(2), 273-291 (2020)). These assays are usually used for in vitro detection of sialic acid, but it is difficult for them to provide dynamic information during physiological and pathological processes in vivo, which limits their further application. Bioimaging can visualize biological species in living cells and contribute to diagnosis and therapy, attracting great attention.

[0006] Reported recognition strategies for glycans (such as sialic acid, polysialic acid, etc.) involve bioaffinity, chemicals, metabolites, and linking labels (Xiong et al., Polymers, 9(7), 249-266 (2017)). The most widely used recognition group is the phenylboronic acid (PBA) moiety, which can form five- or six-membered cyclic esters with the diol moiety of sialic acid. The formed ester is more stable in the cellular environment than other PBA-sugar esters. Therefore, PBA has been introduced into nanoparticles, metal oxide-coated electrodes, organic fluorophores, and lanthanide chelators to provide sensors (Wang, et al., Nanoscale, 10, 4570-4578 (2018)). For example, Lo and colleagues incorporated a PBA group into a cyclometalated iridium(III) bipyridine complex to recognize cellular sialic acid residues and distinguish between cancer cells and normal cells (Liu, et al., Chem.-Asian J., 12, 1545-1556 (2017)). However, the low selectivity due to the binding interaction between PBA and the diol moieties of other monosaccharides affects the accuracy of the sensor. In addition, due to the presence of trace amounts of sialic acid on the surface of normal cells, false positives often occur with the reported probes. There is an urgent need for new and / or improved sialic acid recognition moieties and new and / or improved detection strategies to improve selectivity and avoid false positive results.

[0007] The object of the present invention is to provide compounds for sensing sialic acid and / or lighting up cancer cells, especially for: (1) detecting and visualizing sialic acid, polysialic acid, and glycans; (2) distinguishing cancer cells from normal cells; (3) screening / testing inhibitors for removing sialic acid for the efficiency of therapy.

[0008] Another object of the present invention is to develop methods for imaging sialic acid and / or lighting up cancer cells, especially for: (1) detecting and visualizing glycans (such as sialic acid, polysialic acid, etc.); (2) distinguishing cancer cells from normal cells; (3) screening / testing inhibitors for removing sialic acid for the efficiency of therapy.

[0009] Yet another object of the present invention is to produce kits for imaging and / or lighting up cancer cells with sialic acid, particularly for: (1) detecting and visualizing glycans (such as sialic acid, polysialic acid, etc.); (2) differentiating cancer cells from normal cells; (3) screening / testing inhibitors for removing sialic acid for therapeutic efficiency. Summary of the Invention

[0010] Compounds, mixtures, methods and kits for sensing and / or imaging an analyte, and / or lighting up cells, and / or screening and / or testing inhibitors, and / or early diagnosis and imaging guidance are disclosed.

[0011] In the present application, some examples of compounds will be provided: In some forms, the compound can be a d 8 or d 10 metal complex. A variety of coordination modes contain d 8 metal complexes with a square planar geometry, as well as d 10 metal complexes with a trigonal planar and linear geometry. The compounds generally consist of at least one metal center and at least one coordinating ligand:

[0012] (a) one or more metal centers with a coordination number of 2, 3 or 4, selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), Cu(III), Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II) and Hg(II), and

[0013] (b) one or more ligands with donor atoms selected from carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As) and selenium (Se).

[0014] The formed metal complexes can have planar, partially planar or linear structures. Non-covalent interactions (including electrostatic interactions, hydrogen bond interactions, hydrophobic interactions and their combinations) can promote the binding of the metal complexes to the analyte, resulting in the supramolecular self-assembly of the bound metal complexes through non-covalent metal-metal interactions and / or π-π stacking interactions. The electrostatic and / or non-covalent bound metal complex-analyte adducts or aggregates are further stabilized by the non-covalent metal-metal interactions and / or π-π stacking interactions generated by the self-assembly and / or aggregation of the metal complexes and are not easily disrupted by non-specific interactions. The supramolecular self-assembly of the compounds can be attributed to their planar, partially planar or linear geometric configurations. In some forms, the analyte can be a glycopolymer (such as sialic acid, polysialic acid, etc.); or cancer cells. Glycopolymers (including sialic acid) can be found on the cell surface and play a crucial role in cell transport and signal transduction during physiological processes. In the case of cancer cells, they must evade the detection of the immune system and promote metastatic spread, resulting in elevated levels of sialic acid. This significant difference in glycopolymer levels between cancer cells and normal cells can be used to distinguish different types of cells. Compounds containing positively charged groups and / or amino acids and their derivatives or combinations of amino acids and / or their derivatives have the ability to bind sialic acid and polysialic acid. In addition, these compounds have the ability to self-assemble and, due to the presence of metal centers, their related photophysical properties can be easily probed.

[0015] After adding the analyte, the self-assembly and aggregation of the metal complexes result in significant changes in the photophysical properties of the metal complexes. In some forms, the photophysical properties include absorption and luminescence. In some forms, the change in luminescence can be a red shift or a blue shift in the emission wavelength, or a change in the emission intensity. The change in the photophysical properties can be used as a luminescence signal to detect the analyte.

[0016] In some forms, non-covalent interactions can contribute to the aggregation of the metal complexes. These non-covalent interactions include metal-metal interactions and / or π-π stacking interactions, electrostatic interactions, hydrogen bond interactions, hydrophobic interactions and their combinations. The complex-analyte aggregates formed due to non-covalent interactions endow the metal complexes with the ability to assemble closely and form aggregates, resulting in changes in photophysical properties (such as the luminescence of the metal complexes).

[0017] The specificity of the metal complexes for a specific analyte can be attributed to a combination of one or more non-covalent interactions. As shown in the description and examples, design strategies can be utilized to introduce functional groups for different types of non-covalent interactions between the metal complexes and the analyte to improve specificity. The square planar, partially planar, trigonal planar or linear geometric configurations endow d 8 or d 10The ability of the complexes to stack on top of each other results in the formation of aggregates. Subsequent spectral changes can be used to detect the analyte.

[0018] Introducing a moiety that can bind to the analyte through non-covalent interactions confers high selectivity and specificity of the metal complex towards the analyte of interest. The presence of one or more functional groups can facilitate higher binding affinity by means of a combination of different types of non-covalent interactions.

[0019] Preferably, the analyte contains repeating monomers, which is conducive to the aggregation and self-assembly of the metal complex after binding to the analyte.

[0020] Seven types of chemical formulas (Formulas I - VII) for detecting and / or visualizing analytes are disclosed, wherein the metal complex contains one or more functional groups that bind to the analyte through electrostatic interactions and hydrogen bonds. The supramolecular self-assembly of the metal complex induced by specific interactions leads to luminescence changes, which can be used for detection.

[0021] The compound has a chemical structure as shown in General Formula I:

[0022]

[0023] Wherein:

[0024] (a) M is a metal atom (also known as the metal center). It can be Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), and Cu(III);

[0025] (b) L1, L2, L3, L4 represent ligands. Each ligand can provide one or more donor atoms, preferably one donor atom, for coordination with the metal center;

[0026] (c) n+ / − is the number of charges (positive or negative) carried by the metal complex. n can be zero or a positive integer, such as 1, 2, 3, 4, and 5;

[0027] (d) X is a counterion used to render the compound charge-neutral. When X m- / + is an anion, for example, X m- it can be selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2-) Sulfate (SO4 2- ) Hydrogen phosphate (HPO4 2- ) Phosphate (PO4 3- ) and their derivatives. When X m- / + is a cation, for example X m+ , it can be selected from K + , Na + , Ca 2 + , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ), quaternary ammonium cation and their derivatives;

[0028] (e) m- / + is the number of charges (negative or positive) carried by the counterion. X should carry a charge opposite to that of the metal complex. m can be zero or a positive integer, such as 1, 2, 3, 4, and 5. And where m = n or m ≠ n;

[0029] (f) represents the stoichiometry of the counterion in the formula; and

[0030] (g) The four dashed lines represent an optional independent covalent connection between two ligands, an optional fusion of the ring portions from two ligands, or a combination thereof.

[0031] In some forms, the metal complex has a chemical structure shown in General Formula II:

[0032]

[0033] Wherein:

[0034] (a) M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II).

[0035] (b) L5 and L6 represent ligands. Each ligand can provide at least one donor atom, preferably one donor atom, for coordination with the metal center.

[0036] In some forms, the metal complex has a chemical structure shown in General Formula III, which exhibits a trigonal planar geometry with monodentate, bidentate, and tridentate ligands:

[0037]

[0038] (a) L7, L8, and L9 represent ligands. Each ligand can provide at least one donor atom, preferably one donor atom, for coordination with the metal center.

[0039] In some forms, the ligand has the chemical structure shown in General Formula IV:

[0040]

[0041] Wherein:

[0042] (a) L represents a chemical moiety containing one or more donor atoms, preferably one donor atom, for coordinating with the metal center of the metal complex;

[0043] (b) The linking group represents a structure that can optionally serve as a covalent linking moiety between L and the amino acid / structure containing a positive charge; and

[0044] (c) AA represents an amino acid, or a derivative thereof, or a combination of an amino acid and / or its derivatives, and

[0045] (d) P represents a structure containing a positive charge. The structure with a positive charge can be selected from, but not limited to, substituted and unsubstituted amines, ammonium, pyridinium, pyrrodinium, phosphonium, imidazolium, sulfonium and their derivatives.

[0046] A method for preparing exemplary compounds is also disclosed. This method can be used within a wide range of various functional groups, ligands, metal complexes and compounds, and then various derivatives can be obtained using the disclosed method.

[0047] Also disclosed is a method for detecting polysaccharides (such as sialic acid, polysialic acid); and / or cancer cells. The steps of the assay method are listed as follows: (a) combining a sample (preferably a biological sample) containing an analyte with one or more disclosed compounds; (b) measuring changes in the photophysical properties of the metal complex. Assembly / disassembly is indicated by changes in photophysical properties. Non-covalent interactions such as electrostatic interactions and hydrogen bonds play a huge role in the binding interaction between metal complexes and biological analytes. This binding may lead to changes in the photophysical properties of the metal complex, which can be attributed to the different electron donating or electron withdrawing abilities of certain functional groups present in the metal complex. However, these changes may be unpredictable, and slight changes in the molecular state may affect the detection efficiency, which is a limitation of traditional sensing strategies. As a novel and improved sensing strategy, the self-assembly and aggregation of metal complexes can lead to significant changes in their photophysical properties, providing methods for biological imaging and early diagnosis. (References: Liu, et al., Chem.-Asian J., 12, 1545-1556 (2017); Wang, et al., J. Mat. Chem. B, 9, 4690-4699 (2021); Pancera, et al., Nat. Struct, Mol. Biol., 20, 804-814 (2013)). Changes in photophysical properties indicate the presence of glycans (such as sialic acid, polysialic acid, etc.); and / or cancer cells.

[0048] Methods for imaging glycans (such as sialic acid, polysialic acid, etc.); and cancer cells; and for distinguishing cancer cells from normal cells are also described. The procedure is as follows: (a) one or more disclosed compounds are combined with a sample (preferably a biological sample) under conditions that allow the metal complex to bind to high levels of glycans (such as sialic acid, polysialic acid, etc.). The number of sialic acid molecules on the cell surface of cancer cells can range from 10 4 ~10 11 , 10 5 ~10 11 , 10 6 ~10 11 or 10 7 ~10 11 molecules, especially 10 7 ~10 11A molecule, which can be regarded as a high level. The reported luminescence assays have reported higher levels of sialic acid in cancer cells compared to normal cells. The high density of these sialic acids leads to the self-assembly and aggregation of compounds targeting them in cancer cells (Wang, et al., Anal.Chem., 2017, 89, 538-543; Xu, et al., Talanta, 2020, 209, 120579). Subsequently, the assembly and / or aggregation of metal complexes induces changes in photophysical properties; (b) imaging glycans (such as sialic acid, polysialic acid, etc.) on the cell surface based on changes in one or more photophysical properties; (c) differentiating cancer cells and normal cells based on different luminescence signals. Glycans (including sialic acid) are present on the cell surface and play a crucial role in cell transport and signal transduction during physiological processes. For cancer cells, they must evade the detection of the immune system and promote metastatic spread, resulting in elevated levels of sialic acid. This significant difference in glycan levels between cancer cells and normal cells can be used to distinguish different types of cells. Compounds containing positively charged groups and / or amino acids and their derivatives, or combinations of amino acids and / or their derivatives, have the ability to bind sialic acid and polysialic acid. In addition, these compounds have the ability to self-assemble, and due to the presence of metal centers, their related photophysical properties can be easily detected.

[0049] Methods for testing the efficacy of inhibitors in removing glycans (such as sialic acid, polysialic acid, etc.) from the cell surface are also described. The procedures are listed as follows: (a) combining one or more of the disclosed compounds with inhibitor-treated samples (preferably biological samples), and separately with untreated samples (preferably biological samples) as a control group; (b) comparing the photophysical properties of the metal complexes between the two samples. The aggregation and supramolecular self-assembly of metal complexes cause changes in the photophysical properties of the metal complexes.

[0050] In some forms, the sample can be a human or non-human animal body fluid, a human or non-human animal tissue, or a combination thereof. The body fluid can be cerebrospinal fluid; the tissue can be brain tissue. In some forms, the sample can be eukaryotic cells. These cells can be, but are not limited to, HeLa cells, Hep G2 cells, HEK293T cells, Chinese hamster ovary (CHO) cells, 3T3 cells, A549 cells, and HT1080 cells.

[0051] Kits for detecting and / or imaging glycans (such as sialic acid, polysialic acid, etc.) are also described, which are used to screen or test the efficacy of inhibitors that can remove glycans (such as sialic acid, polysialic acid, etc.) from cancer cells. The kit can contain one or more of the disclosed compounds in one or more containers and optionally instructions for use. The kit can also contain a carrier. Description of the Drawings

[0052] The accompanying drawings incorporated herein and constituting a part of this specification illustrate several embodiments of the disclosed compounds, mixtures, compositions, kits, and methods, and together with the description are used to explain the principles of the disclosed compounds, mixtures, compositions, kits, and methods.

[0053] Figure 1 Shows the cationic d as an illustrative example 8 metal complex (Complex 1-Pt).

[0054] Figure 2 Shows Figure 1 the synthetic route of Complex 1-Pt shown in.

[0055] Figure 3 Shows the UV-visible absorption spectra of Complex 1-Pt (30 μM) after adding different amounts of polysialic acid (0 - 60 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0).

[0056] Figure 4 Shows the UV-visible absorption spectra of Complex 1-Pt (30 μM) after adding different amounts of polysialic acid (60 - 114 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0).

[0057] Figure 5 Shows the emission spectra of Complex 1-Pt (30 μM) after adding different amounts of polysialic acid (0 - 90 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0).

[0058] Figure 6 Shows a plot of the relative emission intensity at 760 nm versus the polysialic acid concentration.

[0059] Figure 7 Shows the corrected emission spectra of Complex 1-Pt (30 μM) after adding different amounts of sialic acid (Neu5Ac) (0 - 90 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0). The arrows indicate the trend of spectral changes.

[0060] Figure 8Bar graphs showing the relative emission intensities at 760 nm of mixtures of complex 1-Pt (30 μM) and different monosaccharides (0, 30, 150, 300 μM), polysialic acid (0, 30, 60, 90 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0). Electrospray ionization mass spectrometry (ESI-MS) results indicated that NEU5AC could bind to the compound. The data showed that monomeric NEU5AC did not cause changes in the photophysical properties. This could be attributed to the monomer's inability to bring the compound close and thus unable to trigger self-assembly and aggregation. In the presence of sialic acid on the branched glycan, the amount rather than the position of the monosaccharide (sialic acid) affected the changes in photophysical properties. Regarding other monosaccharides besides sialic acid, selective assays indicated that they could not bind to the compound, thus providing good selectivity.

[0061] Figures 9A - 9J show luminescence confocal images of live HeLa cells stained with different concentrations of 10 μM (Figures 9A - 9C), 20 μM (Figures 9D - 9F), 30 μM (Figures 9G - 9I) of complex 1-Pt for 1 h at 37 °C. (Figures 9A, 9E, and 9H) Bright field; (Figures 9B, 9E, and 9H) Luminescence confocal images with emission collected at 700 - 800 nm; (Figures 9C, 9F, and 9I) Merged confocal images with bright field and emission collected at 700 - 800 nm; (Figure 9J) is a bar graph comparing the relative emission intensities between different concentrations.

[0062] Figures 10A - 10P show luminescence confocal images of live HepG2 cells incubated with complex 1-Pt (10 μM) at 37 °C for 0.5 h (Figures 10A, 10F, and 10K), 1 h (Figures 10B, 10G, and 10L), 2 h (Figures 10C, 10H, and 10M), 6 h (Figures 10D, 10I, and 10N), 8 h (Figures 10E, 10J, and 10O). (10A - 10E) Luminescence confocal images with emission collected at 700 - 800 nm; (Figures 10F - 10J) Bright field; (Figures 10K - 10O) Merged confocal images with bright field and emission collected at 700 - 800 nm; (Figure 10P) is a bar graph comparing the relative emission intensities of complex 1-Pt over time for the cases of 0.5 h, 2 h, 6 h, and 8 h.

[0063] Figures 11A - 11G show luminescence confocal images of live HepG2 cells (Figs. 11A - 11C) and live HEK293T cells (Figs. 11D - 11F) stained with complex 1 - Pt (10 μM) for 0.5 h at 37°C. (Figs. 11A, 11D) are luminescence confocal images with emission collected at 700 - 800 nm; (Figs. 11B, 11E) are bright - field views; (Figs. 11C, 11F) are merged confocal images with bright - field and emission collected at 700 - 800 nm; (Fig. 11G) is a bar graph comparing the relative emission intensities between HepG2 cells and HEK293T cells stained with complex 1 - Pt.

[0064] Figures 12A - 12G show luminescence confocal images of live HeLa cells (Figs. 12A - 12C) and live HEK293T cells (Figs. 12D - 12F) stained with complex 1 - Pt (10 μM) for 0.5 h at 37°C. (Figs. 12A, 12D) are luminescence confocal images with emission collected at 700 - 800 nm; (Figs. 12B, 12E) are bright - field views; (Figs. 12C, 12F) are merged confocal images with bright - field and emission collected at 700 - 800 nm; (Fig. 12G) is a bar graph comparing the relative emission intensities between HeLa cells and HEK293T cells stained with complex 1 - Pt.

[0065] Figures 13A - 13D show luminescence confocal images of live HepG2 cells stained with complex 1 - Pt (10 μM) for 0.5 h, then incubated with paraformaldehyde fixation solution for 15 min, and then incubated with FITC - conjugated lectin (20 μg / mL) for 1 h (Figs. 13A - 13D). (Fig. 13A) is a luminescence confocal image with emission collected at 700 - 800 nm and an excitation wavelength of 405 nm; (Fig. 13B) is a luminescence confocal image with emission collected at 500 - 550 nm and an excitation wavelength of 488 nm; (Fig. 13C) is a merged confocal image with emission collected at 700 - 800 nm and 500 - 550 nm; (Fig. 13D) is the intensity curve of (Fig. 13A) and (Fig. 13B); (Fig. 13E) shows a line graph of the overlapping luminescence signals of complex 1 - Pt and a commercial dye with the marked line (-) in Fig. 13C.

[0066] Figures 14A - 14E show luminescence confocal images of live HepG2 cells stained with complex 1 - Pt (10 μM) for 0.5 h and then incubated with a membrane tracer (5 μg / mL) for 10 minutes. (Figure 14A) Luminescence confocal image with emission collected at 700 - 800 nm and an excitation wavelength of 405 nm; (Figure 14B) Luminescence confocal image with emission collected at 650 - 670 nm and an excitation wavelength of 635 nm; (Figure 14C) Bright - field; (Figure 14D) Merged confocal image with emission collected at 700 - 800 nm and 650 - 670 nm; (Figure 14E) Line graph showing the overlapping luminescence signals of live HepG2 cells stained with complex 1 - Pt with the marker line (-) in Figure 14D relative to a commercial dye.

[0067] Figures 15A - 15G show luminescence confocal images of live HepG2 cells treated with neuraminidase for 1 h (Figures 15D - 15F) and untreated with neuraminidase (Figures 15A - 15C). (Figures 15A and 15D) Luminescence confocal images with emission collected at 700 - 800 nm; (Figures 15B and 15E) Bright - field; (Figures 15C and 15F) Merged confocal images of bright - field and emission collected at 700 - 800 nm at an excitation wavelength of 405 nm; (Figure 15G) Bar graph comparing the relative emission intensities between HepG2 cells treated with and without neuraminidase.

[0068] Figure 16 is a bar graph showing the cell viability of HepG2 cells incubated with different concentrations of complex 1 - Pt (0.78, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 μM) after incubation at 37 °C for 24 h.

[0069] Figures 17A - 17E show luminescence confocal images of live HEK293T cells stained with complex 1 - Pt (10 μM) for 0.5 h, then incubated with a paraformaldehyde fixation solution for 15 min, and incubated with FITC - conjugated lectin (20 μg / mL) for 1 h. (Figure 17A) Luminescence confocal image with emission collected at 700 - 800 nm and an excitation wavelength of 405 nm; (Figure 17B) Luminescence confocal image with emission collected at 500 - 550 nm and an excitation wavelength of 488 nm; (Figure 17C) Merged confocal image with emission collected at 700 - 800 nm and 500 - 550 nm; (Figure 17D) Bright - field; (Figure 17E) Line graph showing the overlapping luminescence signals of complex 1 - Pt with the marker line (-) in Figure 17C and a commercial dye.

[0070] Figures 18A to 18C show (Figure 18A) luminescent confocal images of live HepG2 cells and (Figure 18B) live HEK293T cells stained with complex 9-Pt (10 μM) for 0.5 h at 37°C. (Figures 18A to 18B) Merged confocal images with bright field and emission collected at 700 to 800 nm; (Figure 18C) Bar graph comparing relative emission intensity between HepG2 and HEK293T stained with complex 9-Pt.

[0071] Figures 19A to 19C show (Figure 19A) luminescent confocal images of live HepG2 cells and (Figure 19B) live HEK293T cells stained with complex 10-Pt (10 μM) for 0.5 h at 37°C. (Figures 19A to 19B) Merged confocal images with bright field and emission collected at 700 to 800 nm; (Figure 19C) Bar graph comparing relative emission intensity between HepG2 cells and HEK293T cells stained with complex 10-Pt. DETAILED DESCRIPTION

[0072] Disclosed are compounds, compositions, methods and kits for detecting and / or visualizing analytes and / or screening inhibitors, particularly for: (1) detecting glycans (such as sialic acid, polysialic acid, etc.) in a buffer, an aqueous environment, an aqueous-organic solvent mixture environment or any other medium; (2) visualizing high levels of glycans (such as sialic acid, polysialic acid, etc.) on the surface of cancer cells, with a concentration range of 10 4 ~10 11 , 10 5 ~10 11 , 10 6 ~10 11 or 10 7 ~10 11 molecules, especially 10 7 ~10 11 molecules, which can be considered a high level. Reported luminescence assays have reported higher levels of sialic acid in cancer cells compared to normal cells. The high density of these sialic acids leads to self-assembly and aggregation of compounds targeting them in cancer cells. (Wang, et al., Anal. Chem., 2017, 89, 538-543; Xu, et al., Talanta, 2020, 209, 120579); (3) distinguishing cancer cells from normal cells to detect or diagnose signs of cancer; and / or (4) screening and / or testing the efficacy of inhibitors to remove sialic acid on the surface of cancer cells for anticancer therapy.

[0073] In some forms, the compound includes a d 8 or 10Metal complexes. The analyte can be a glycan (such as sialic acid, polysialic acid, etc.) or a cancer cell. The binding can generate a luminescence signal in the red to near-infrared (NIR) region via the aggregation and supramolecular self-assembly of the metal complex through non-covalent metal-metal and / or π-π interactions. The non-covalent interactions include π-π stacking interactions, electrostatic interactions, hydrogen bond interactions, hydrophobic interactions, and combinations thereof, which can promote the binding between the metal complex and the analyte, thereby inducing the supramolecular self-assembly and / or aggregation of the metal complex. The electrostatic and / or non-covalent bound metal complex-analyte adduct or aggregate is further stabilized by the non-covalent metal-metal interactions and / or π-π stacking interactions generated by the self-assembly and / or aggregation of the metal complex and is not easily disrupted by non-specific interactions. Along with the excitation wavelength in the visible region and a large Stokes shift, the interference caused by autofluorescence frequently encountered in the presence of various biological substrates can be reduced, making the compound suitable for use in biological assays.

[0074] The disclosed compounds, compositions, kits, and methods can be more readily understood by reference to the detailed description of the following specific embodiments, the examples contained therein, and the accompanying drawings and the description before and after them. Unless otherwise stated or clearly contradicted by the context, all methods described herein can be performed in any suitable order.

[0075] Unless otherwise stated, the use of any and all examples or exemplary language (e.g., "such as") provided herein is only intended to better illustrate the invention and does not constitute a limitation on the scope of the invention. No language in the specification should be construed as indicating that any unclaimed element is essential for the practice of the invention.

[0076] The disclosed compounds, compositions, and kits can be used in the disclosed methods, can be used in combination with the disclosed methods, can be used to prepare the disclosed methods, or are products of the disclosed methods. It should be understood that when combinations, subsets, interactions, groups, etc. of these compounds, compositions, and kits are disclosed, each distinct individual and collective combination of these materials is specifically contemplated and described herein, even though specific references to each may not be explicitly disclosed. For example, if a compound is disclosed and discussed, and a variety of modifications that can be made to many molecules including that compound are discussed, then each combination and permutation of that compound and possible modifications is specifically contemplated unless explicitly indicated to the contrary. Thus, if a class of molecules A, B, and C is disclosed, and a class of molecules D, E, and F is disclosed, and an example of a combined molecule A-D is disclosed, then each combination is specifically contemplated both individually and collectively, even if each combination is not separately recited. Thus, in this example, each of the combinations A-E, A-F, B-D, B-E, B-F, C-D, C-E, and C-F is specifically contemplated and should be considered disclosed from the disclosure of A, B, and C; D, E, and F; and the example combination A-D. Similarly, any subset or combination of these is specifically contemplated and disclosed. Thus, for example, the sub-groups A-E, B-F, and C-E are specifically contemplated and should be considered disclosed from the disclosure of A, B, and C; D, E, and F; and the example combination A-D. In addition, each compound, composition, kit, component, etc. as specifically contemplated and disclosed above can be specifically and independently included or excluded from any group, sub-group, list, set, etc. of these materials. These concepts apply to all aspects of this application, including but not limited to steps in methods of making and using the disclosed compounds, compositions, and kits. Thus, if there are various additional steps that can be taken, it should be understood that each of these additional steps can be carried out with any particular embodiment or combination of embodiments of the disclosed methods, and each such combination is specifically contemplated and should be considered disclosed.

[0077] Throughout the description and claims of this specification, the word "include" and variations of that word, such as "including" mean "including but not limited to" and are not intended to exclude, for example, other additives, components, integers, or steps.

[0078] Any discussion of documents, acts, materials, devices, articles, etc. that has been included in this specification should not be taken to mean that any or all of these constitute a part of the prior art base or are common general knowledge in the relevant field of this disclosure as of the priority date of each claim of this application.

[0079] I. Definitions

[0080] In this application, unless otherwise specified, the following terms shall be construed as having the meanings set forth below:

[0081] Unless the context clearly indicates otherwise, the articles "a / an" and "the" include plural referents. For example, "a complex" includes a plurality of complexes, and reference to "the compound" refers to reference to one or more compounds and equivalents thereof known to those skilled in the art.

[0082] The terms "may", "can", "could", "might", "should", and related terms may be used to indicate that the subject matter involved is optional (i.e., the subject matter is present in some embodiments and absent in other embodiments), without referring to the ability or possibility of the subject matter, unless the context clearly indicates otherwise.

[0083] The terms "optional" and "optionally" may be used to indicate that the subsequent described event, circumstance, or material may or may not occur, or may or may not be present, and the description includes the cases where the event, circumstance, or material occurs or is present and the cases where it does not occur or is not present.

[0084] The term "about" can be used to describe a value that is above or below a specified value within a range of about + / - 10%; in other embodiments, the value can vary among values that are above or below the specified value within a range of about + / - 5%; in other embodiments, the value can vary among values that are above or below the specified value within a range of about + / - 2%; in other embodiments, the value can vary among values that are above or below the specified value within a range of about + / - 1%. The foregoing ranges are intended to be clearly described by the context and do not imply further limitations. The range can be clearly described by the context and will not show further limitations. The range can be expressed herein as from "about" a particular value and / or to "about" another particular value. When expressing such a range, unless the context clearly indicates otherwise, the range from a particular value and / or to another particular value should also be clearly covered and considered disclosed. Similarly, when a value is expressed as an approximation by using the antecedent "about", it should be understood that the particular value forms another clearly covered embodiment, which should be considered disclosed unless the context clearly indicates otherwise. It is further understood that, unless the context clearly indicates otherwise, each endpoint of a range is significant relative to the other endpoint and is independent of the other endpoint. It should be understood that all individual values and sub-ranges of values included within the clearly disclosed range should also be clearly covered and should be considered disclosed, unless the context clearly indicates otherwise. Finally, it should be understood that all ranges refer both to the recited ranges as ranges and to the set of individual numbers from the first endpoint (including the first endpoint) to the second endpoint (including the second endpoint). In the latter case, it should be understood that any single number can be selected as a form of the quantity, value, or feature referred to by the range. In this way, the range describes a set of numbers or values from the first endpoint (including the first endpoint) to the second endpoint (including the second endpoint), from which a single member (i.e., a single number) of the set can be selected as the quantity, value, or feature referred to by the range. The foregoing applies regardless of whether some or all of these embodiments are clearly disclosed in a particular case.

[0085] The carbon range (e.g., C1 to C 10 ) is intended to separately disclose each possible carbon value and / or the sub-ranges contained therein. For example, the carbon length range of C1 to C 10 discloses C1, C2, C3, C4, C5, C6, C7, C8, C9, and C 10 , and also discloses the sub-ranges contained therein, such as C2 to C9, C3 to C8, C1 to C5, etc.

[0086] The term "derivative" can be used to denote a compound that is similar to a parent compound but is different therefrom in terms of functional groups, atoms, etc. They may follow a specific chemical structure. A series of chemical structures of derivatives can be generated by replacing one or more functional groups, or introducing or removing substituents of one or more hydrogen atoms of the parent compound.

[0087] The term "halogen" refers to fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

[0088] The term "alkyl" refers to a monovalent group obtained from an alkane by removing a hydrogen atom from any carbon atom. Alkanes represent saturated hydrocarbons, including those that are cyclic (monocyclic or polycyclic). Alkyl can be straight-chain, branched-chain, or cyclic. Preferred alkyls have 1 to 30 carbon atoms, i.e., C1-C 30 alkyl. In some forms, C1-C 30 alkyl can be straight-chain C1-C 30 alkyl, branched-chain C1-C 30 alkyl, cyclic C1-C 30 alkyl, straight-chain or branched-chain C1-C 30 alkyl, straight-chain or cyclic C1-C 30 alkyl, branched-chain or cyclic C1-C 30 alkyl, or straight-chain, branched-chain or cyclic C1-C 30 alkyl.

[0089] The term "heteroalkyl" refers to an alkyl in which one or more carbon atoms are replaced by heteroatoms (such as O, N, or S). Heteroalkyl can be straight-chain, branched-chain, or cyclic (monocyclic or polycyclic). Preferred heteroalkyls have 1 to 30 carbon atoms, i.e., C1-C 30 heteroalkyl. In some forms, C1-C 30 heteroalkyl can be straight-chain C1-C 30 heteroalkyl, branched-chain C1-C 30 heteroalkyl, cyclic C1-C 30 heteroalkyl, straight-chain or branched-chain C1-C 30 heteroalkyl, straight-chain or cyclic C1-C 30 heteroalkyl, branched-chain or cyclic C1-C 30 heteroalkyl, or straight-chain, branched-chain or cyclic C1-C 30 heteroalkyl.

[0090] The term "alkenyl" refers to a monovalent group obtained from an alkene by removing a hydrogen atom from any carbon atom. Alkenes are unsaturated hydrocarbons containing at least one carbon-carbon double bond. Alkenyl can be straight-chain, branched-chain, or cyclic (monocyclic or polycyclic). Preferred alkenyls have 1 to 30 carbon atoms, i.e., C2-C 30 alkenyl. In some forms, C2-C30 The alkenyl group can be a straight-chain C2-C 30 alkenyl group, a branched-chain C2-C 30 alkenyl group, a cyclic C2-C 30 alkenyl group, a straight-chain or branched-chain C2-C 30 alkenyl group, a straight-chain or cyclic C2-C 30 alkenyl group, a branched-chain or cyclic C2-C 30 alkenyl group, or a straight-chain, branched-chain or cyclic C2-C 30 alkenyl group.

[0091] The term "heteroalkenyl" refers to an alkenyl group in which one or more carbon atoms linked by a double bond are replaced by a heteroatom. The heteroalkenyl group can be straight-chain, branched-chain or cyclic (monocyclic or polycyclic). Preferred heteroalkenyl groups have 1 to 30 carbon atoms, i.e., C1-C 30 heteroalkenyl group. In some forms, C1-C 30 the alkenyl group can be a straight-chain C1-C 30 heteroalkenyl group, a branched-chain C1-C 30 heteroalkenyl group, a cyclic C1-C 30 heteroalkenyl group, a straight-chain or branched-chain C1-C 30 heteroalkenyl group, a straight-chain or cyclic C1-C 30 heteroalkenyl group, a branched-chain or cyclic C1-C 30 heteroalkenyl group, or a straight-chain, branched-chain or cyclic C1-C 30 heteroalkenyl group.

[0092] The term "alkynyl" refers to a monovalent group obtained from an alkyne by removing a hydrogen atom from any carbon atom. An alkyne is an unsaturated hydrocarbon containing at least one carbon-carbon triple bond. The alkynyl group can be straight-chain, branched-chain or cyclic (monocyclic or polycyclic). Preferred alkynyl groups have 1 to 30 carbon atoms, i.e., C2-C 30 alkynyl group. In some forms, C2-C 30 the alkynyl group can be a straight-chain C2-C 30 alkynyl group, a branched-chain C2-C 30 alkynyl group, a cyclic C2-C 30 alkynyl group, a straight-chain or branched-chain C2-C 30 alkynyl group, a straight-chain or cyclic C2-C 30 alkynyl group, a branched-chain or cyclic C2-C 30 alkynyl group, or a straight-chain, branched-chain or cyclic C2-C 30 alkynyl group.

[0093] The term "heteroalkynyl" refers to an alkynyl group in which one or more carbon atoms linked by a triple bond are replaced by a heteroatom. The heteroalkynyl group can be straight-chain, branched-chain or cyclic (monocyclic or polycyclic). Preferred heteroalkynyl groups have 1 to 30 carbon atoms, i.e., C2-C 30 heteroalkynyl group. In some forms, C2-C 30The alkynyl group can be a straight-chain C2-C 30 heteroalkynyl group, a branched-chain C2-C 30 heteroalkynyl group, a cyclic C2-C 30 heteroalkynyl group, a straight-chain or branched-chain C2-C 30 heteroalkynyl group, a straight-chain or cyclic C2-C 30 heteroalkynyl group, a branched-chain or cyclic C2-C 30 heteroalkynyl group, or a straight-chain, branched-chain or cyclic C2-C 30 heteroalkynyl group.

[0094] The term "aryl" refers to a monovalent group obtained from an aromatic hydrocarbon by removing a hydrogen atom from a ring atom. An aromatic hydrocarbon is a monocyclic or polycyclic aromatic hydrocarbon. In a polycyclic aromatic hydrocarbon, the rings can be linked together in a pendant fashion or can be fused. Preferred aromatic hydrocarbons have 6 to 50 carbon atoms, i.e., C6-C 50 aromatic hydrocarbon. In some forms, C6-C 50 The alkynyl group can be a straight-chain C6-C 50 aromatic hydrocarbon, a branched-chain C6-C 50 aromatic hydrocarbon, a cyclic C6-C 50 aromatic hydrocarbon, a straight-chain or branched-chain C6-C 50 aromatic hydrocarbon, a straight-chain or cyclic C6-C 50 aromatic hydrocarbon, a branched-chain or cyclic C6-C 50 aromatic hydrocarbon, or a straight-chain, branched-chain or cyclic C6-C 50 aromatic hydrocarbon. Thus, in a polycyclic aryl group, the rings can be linked together in a pendant fashion or can be fused. Preferred aryl groups have 6 to 50 carbon atoms, i.e., C6-C 50 aryl group. In some forms, C6-C 50 The aryl group can be a branched-chain C6-C 50 aryl group, a monocyclic C6-C 50 aryl group, a polycyclic C6-C 50 aryl group, a branched-chain polycyclic C6-C 50 aryl group, a fused polycyclic C6-C 50 aryl group or a branched-chain fused polycyclic C6-C 50 aryl group.

[0095] The term "heteroaryl" refers to a monovalent group obtained from a heteroaromatic hydrocarbon by removing a hydrogen atom from a ring atom. A heteroaromatic hydrocarbon is a heterocyclic compound obtained from an aromatic hydrocarbon by replacing one or more methylene (-HC=) and / or vinylene (-CH=CH-) groups with trivalent or divalent heteroatoms, in such a way as to maintain the characteristic of the continuous π-electron system of the aromatic system and the number of out-of-plane π-electrons corresponding to Hückel's rule (4n + 2). The heteroaromatic hydrocarbon can be monocyclic or polycyclic. In a polycyclic heteroaromatic hydrocarbon, the rings can be linked together in a pendant fashion or can be fused. Preferred heteroaromatic hydrocarbons have 3 to 50 carbon atoms, i.e., C3-C 50Heteroarenes. In some forms, C3-C 50 The heteroarene can be a branched C3-C 50 heteroarene, a monocyclic C3-C 50 heteroarene, a polycyclic C3-C 50 heteroarene, a branched polycyclic C3-C 50 heteroarene, a fused polycyclic C3-C 50 heteroarene or a branched fused polycyclic C3-C 50 heteroarene. Thus, in a polycyclic heteroaryl, the rings can be joined together in a pendant fashion or can be fused. Preferred heteroaryls have 3 to 50 carbon atoms, i.e., C3-C 50 heteroaryl. In some forms, C3-C 50 The heteroaryl can be a branched C3-C 50 heteroaryl, a monocyclic C3-C 50 heteroaryl, a polycyclic C3-C 50 heteroaryl, a branched polycyclic C3-C 50 heteroaryl, a fused polycyclic C3-C 50 heteroaryl, or a branched fused polycyclic C3-C 50 heteroaryl.

[0096] The term "arylene" refers to a divalent group obtained from an arene by removing hydrogen atoms from two ring carbon atoms. In a polycyclic arylene, the rings can be joined together in a pendant fashion or can be fused. Preferred arylenes have 6 to 50 carbon atoms, i.e., C6-C 50 arylene. In some forms, C6-C 50 The arylene can be a branched C6-C 50 arylene, a monocyclic C6-C 50 arylene, a polycyclic C6-C 50 arylene, a branched polycyclic C6-C 50 arylene, a fused polycyclic C6-C 50 arylene or a branched fused polycyclic C6-C 50 arylene.

[0097] The term "heteroarylene" refers to a divalent group obtained from a heteroarene by removing hydrogen atoms from two ring atoms. In a polycyclic heteroarylene, the rings can be joined together in a pendant fashion or can be fused. Preferred heteroarylenes have 3 to 50 carbon atoms, i.e., C3-C 50 heteroarylene. In some forms, C3-C 50 The heteroarylene can be a branched C3-C 50 heteroarylene, a monocyclic C3-C 50 heteroarylene, a polycyclic C3-C 50 heteroarylene, a branched polycyclic C3-C 50 heteroarylene, a fused polycyclic C3-C50 A heteroaryl or branched fused polycyclic C3-C 50 heteroaryl.

[0098] The term "aminooxy" refers to -O-NH2, where the hydrogen atom can be substituted by a substituent.

[0099] The term "hydroxyamino" refers to -NH-OH, where the hydrogen atom can be substituted by a substituent.

[0100] The term "hydroxamic acid" refers to -(C═O)-NH-OH, where the hydrogen atom can be substituted by a substituent.

[0101] The term "conjugated system" refers to the following molecular entity: the structure of the molecular entity can be represented as an alternating single bond and multiple bond system, such as -CH2═CH--CH═CH2, -CH2═CH-C≡N-. In such a system, conjugation refers to the interaction of one p orbital with another p orbital through an intervening σ bond in such a structure. A conjugated system can be or contain an aromatic and / or heteroaromatic moiety.

[0102] As used herein, the term "substituted" means that a chemical group or moiety contains one or more substituents that replace a hydrogen atom in the chemical group or moiety. Substituents include, but are not limited to: halogen atoms, alkyl groups, heteroalkyl groups, alkenyl groups, heteroalkenyl groups, alkynyl groups, heteroalkynyl groups, aryl groups, heteroaryl groups, -OH, -SH, -NH2, -N3, -OCN, -NCO, -ONO2, -CN, -NC, -ONO, -CONH2, -NO, -NO2, -ONH2, -SCN, -NCS, -CF3, -CH2CF3, -CH2Cl, -COF, -COBr, -COOH, -S3H, -CH2SO2CH3, -PO3H2, -OPO3H2, -P(═O)(OR G1’ )(OR G2’ )、-OP(═O)(OR G1’ )(OR G2’ )、-BR G1’ (OR G2’ )、-B(OR G1’ )(OR G2’ ) or -G’R G1’ , where -G’ is -O-, -S-, -NR G2’ -, -C(═O)O-, -C(═O)-, -S(═O)-, -SO2-, -C(═O)O-, -C(═O)NR G2’ -, -NR G2’ C(O)-, -NR G2’ C(═O)NR G3’-, -C(═S)-, -C(═S)S-, -SC(═S)-, -SC(═S)S-, -C(═NR G2’ )-, -C(═NR G2’ )O-, -C(═NR G2’ )R G3’ -, -OC(═NR G2’ )-, -NR G2’ C(═NR G3’ )-, -NR G2’ SO2-, -C(═NR G2’ )NR G’ )-, -OC(═NR G2’ )-, -NR G2’ SO2NR G3’ -, NR G2’ C(═S)-, -SC(═S)NR G2’ -, -NR G2’ C(═S)S-, -NR G2’ C(═S)NR G3’ -, -SC(═NR G2’ )-, -C(═S)NR G2’ -, -OC(═S)NR G2’ -, -NR G2’ C(═S)O-, -SC(═O)NR G2’ -, -NR G2’ C(O)S-, -C(O)S-, -SC(O)-, -SC(O)S-, -C(═S)O-, -OC(═S)-, -OC(═S)O-, -SO2NR G2’ -, -Br G2’ - or -Pr G2’ -.

[0103] Wherein each occurrence of R G1’ , R G2’ and R G3’ is independently a hydrogen atom, a halogen atom, an alkyl group, a heteroalkyl group, an alkenyl group, a heteroalkenyl group, an alkynyl group, a heteroalkynyl group, an aryl group or a heteroaryl group.

[0104] In some cases, "substituted" also refers to the substitution of one or more carbon atoms in a carbon chain (such as, but not limited to, an alkyl group, an alkenyl group, an alkynyl group and an aryl group) by one or more heteroatoms (such as, but not limited to, nitrogen, oxygen and sulfur, etc.).

[0105] It should be understood that "substituted" or "substitution" includes the implicit condition that such substitution conforms to the allowed valences of the atoms being substituted and the substituents, and the substitution results in a stable compound, i.e., a compound that does not spontaneously undergo transformations (such as rearrangement, cyclization, elimination, etc.).

[0106] The term "d 8 or d 10 metal complex" and "multiple d 8 or d 10 metal complexes" can be any complex containing at least one metal center having a d 8 or d 10 electron configuration. The term "d 8 or d 10 metal complex aggregate" refers to the local concentration enrichment of d 8 or d 10 metal complexes near the analyte. The analyte can be sialic acid or polysialic acid, glycans, or cancer cells. The local concentration enrichment can be caused by non-covalent metal-metal interactions between d 8 or d 10 metal complex molecules. Non-covalent interactions such as π-π stacking interactions, electrostatic interactions, hydrogen bond interactions, and hydrophobic interactions and combinations thereof can contribute to the binding between the analyte and d 8 or d 10 metal complexes and between d 8 or d 10 different molecules of the metal complex. In some forms, d 8 or d 10 metal complex aggregates can be formed via the aggregation and supramolecular self-assembly of d 8 or d 10 metal complexes after binding to the analyte. The metal center can be selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), Cu(III), Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II).

[0107] The term "ligand" refers to an ion or molecule that binds to a metal center through one or more donor atoms to form a metal complex. The nature of the metal-ligand bond can range from covalent to ionic. The bond order of the metal-ligand can range from one to three. Bonding to the metal center typically involves the formal donation of one or more electron pairs from the donor atoms. The donor atoms can be carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As), and selenium (Se).

[0108] The term "coordination number" refers to the total number of donor atoms.

[0109] The term "sialic acid" as used in this application can be a member of a class of α-ketoacid sugars sharing a nine-carbon backbone.

[0110] The term "polysialic acid" as used in this application can be a polymer of linear repeating monomer units of α-2,8- and α-2,9-glycosidically linked sialic acid residues.

[0111] The term "luminescence" refers to the emission of light by a substance that is not caused by heat. Luminescence can be caused by chemical reactions, electrical energy, subatomic motion, or stress on a crystal, all of which ultimately result from spontaneous emission. Luminescence can refer to chemiluminescence, i.e., the emission of light due to a chemical reaction. Luminescence can also refer to photoluminescence, i.e., the emission of light due to photon absorption. Photoluminescence includes fluorescence and phosphorescence, thermally activated delayed fluorescence (TADF), thermally stimulated delayed phosphorescence (TSDP), upconversion luminescence, and other forms of photoexcited luminescence.

[0112] The term "carrier" refers to all components of a formulation or composition other than one or more active ingredients. They can include, but are not limited to, diluents, binders, lubricants, disintegrants, fillers, plasticizers, pigments, colorants, stabilizers, and glidants.

[0113] As used herein, "subject" includes, but is not limited to, human or non-human mammals. The term does not denote a particular age or sex. Thus, adult and neonatal subjects as well as fetuses (whether male or female, or hermaphroditic) are intended to be included.

[0114] It should be understood that, unless otherwise specified, the disclosed methods and compositions are not limited to particular synthetic methods, particular analytical techniques, or particular reagents, and thus can vary. It should also be understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting.

[0115] It should also be understood that when a certain geometric configuration is assigned to a compound, such as linear, trigonal planar, and square planar, the assigned geometric configuration can be determined based on the atoms in the ligands participating in the bonding to the central metal atom.

[0116] II. Compositions

[0117] Compounds are disclosed that can be used to detect and / or visualize an analyte or to test the efficacy of an inhibitor. In some forms, the analyte can be sialic acid, polysialic acid, glycan, and cancer cells. The disclosed compounds can be used to sense the analyte and distinguish cancer cells from normal cells. The compound can be used to detect or diagnose signs of cancer. The compound can also be used to screen for inhibitors that can remove glycans (such as sialic acid, polysialic acid, etc.) from the cell surface for therapeutic use. Some examples will be provided in this application. In some forms, the compound is a metal complex having a d 8 or d 10 electronic configuration, the metal complex consisting of at least one metal center and at least one coordinating ligand:

[0118] (a) A metal center with a coordination number of 2, 3 or 4, selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), Cu(III), Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II) and Hg(II); and / or

[0119] One or more ligands having donor atoms selected from carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As) and selenium (Se).

[0120] A. Metal complex or compound

[0121] d 8 or d 10 The metal complex exhibits a square planar, trigonal planar, partially planar or linear structure, and these geometries facilitate the stacking of metal complexes with each other to produce aggregates. The self-assembled structures and / or aggregates can form highly ordered linear structures, oligomers or layered superstructures. Non-covalent interactions induced by introducing specific functional groups endow the metal complex with the ability to bind to an analyte of interest. Non-limiting examples of the functional groups driving this specificity are listed below.

[0122] They may be selected from positively charged functional groups:

[0123]

[0124] They may be selected from amino acids and / or their derivatives, or combinations of amino acids and / or their derivatives:

[0125]

[0126] The non-covalent interactions may include electrostatic interactions, hydrogen bond interactions, hydrophobic interactions and combinations thereof. The specific binding interaction between the metal complex and the analyte causes adjacent complex molecules to approach, resulting in the supramolecular self-assembly of the metal complex. The metal complex-analyte adduct or aggregate bound by electrostatic and / or non-covalent interactions is further stabilized by non-covalent metal-metal interactions and / or π-π stacking interactions generated by the self-assembly and / or aggregation of the metal complex, and is not easily disrupted by non-specific interactions.

[0127] In some forms, the analyte that can induce the assembly / decomposition of the metal complex can be sialic acid or polysialic acid, or a glycan, or a cancer cell. Sialic acid shares a nine-carbon backbone and is usually located at the outermost end of the glycan chain of all cell types. The analyte also includes dimers, trimers or polymers containing sialic acid.

[0128] In some forms, the metal complex can bind to some types of monosaccharides, including but not limited to monosaccharides, disaccharides, and polysaccharides. The molecular formula of a monosaccharide is C n H 2n O n . Examples of monosaccharides can be, but are not limited to, glucose, galactose, fructose, etc. Examples of disaccharides can be, but are not limited to, sucrose, lactose, etc. Examples of polysaccharides can be, but are not limited to, cellulose, starch, etc. The specific binding interaction between the compound and the analyte promotes the self-assembly and aggregation of the metal complex. The self-assembly and / or aggregation of the metal complex induces changes in the photophysical properties of the metal complex. The photophysical properties can be, but are not limited to, absorbance, luminescence, circular dichroism, circularly polarized luminescence, or a combination thereof.

[0129] In some forms, a change in the luminescence intensity upon addition of the analyte as shown Figure 5 can be observed. Preferably, a significant difference in the emission wavelength or energy in the absence and presence of the analyte can be observed. Non-covalent interactions including electrostatic interactions, hydrogen bond interactions, hydrophobic interactions, and combinations thereof facilitate the interaction between the metal complex and the analyte, resulting in the supramolecular self-assembly of the metal complex. The change in the photophysical properties can be or include a change in the luminescence band from red light to near-infrared (NIR I and NIR II) emission, for example, in the range of about 600 nm to about 1700 nm. The change includes a blue shift or a red shift in the emission energy or wavelength or emission intensity, which is caused by a change in the supramolecular self-assembly of the metal complex. In some forms, a large Stokes shift can also be observed. In some forms, the Stokes shift is greater than 100 nm, greater than 150 nm, greater than 200 nm, greater than 250 nm, greater than 300 nm, greater than 350 nm, or greater than 400 nm. More preferably, the Stokes shift is greater than 400 nm.

[0130] In some forms, the specificity of the metal complex for the analyte can be attributed to one or more specific non-covalent interactions. To obtain better specificity, design strategies can be used to introduce more than one non-covalent interaction. Then, planar, trigonal planar, partially planar, or linear geometries confer on the metal complex a tendency to form highly ordered structures. The binding interaction between the metal complex and the analyte will bring the metal complex molecules closer together, promoting the formation of self-assembly and / or aggregation. The metal complex can be designed to bind to the analyte of interest by selecting the metal center and / or the coordinating ligands, especially the functional groups on the metal complex ligands. The self-assembly of the metal complex can be known, which greatly facilitates the design of these detection methods.

[0131] In some forms, d 8 or d 10Metal complexes are selected as sensors that bind to an analyte. Introducing one or more specific functional groups into the ligand results in a high propensity for the metal complex to form strong binding interactions with the analyte, thereby enhancing specificity. Combinations of different metal centers and ligands will yield useful sensors for binding to the analyte.

[0132] In some forms, the repetitive highly ordered structure of the analyte promotes supramolecular self-assembly of the metal complex after binding. In some forms, electrostatic interactions between a charged metal complex and an analyte with an opposite electrostatic charge can promote binding between the two. In some forms, hydrogen bonds between the metal complex and the analyte can contribute to strong binding interactions. In some forms, other non-covalent interactions including, but not limited to, hydrophobic interactions and π-π stacking interactions can contribute to the binding interaction between the metal complex and the analyte. The electrostatically and / or non-covalently bound metal complex-analyte adducts or aggregates are further stabilized by non-covalent metal-metal interactions and / or π-π stacking interactions resulting from the self-assembly and / or aggregation of the metal complexes and are not readily disrupted by non-specific interactions.

[0133] B. Ligands of Metal Complexes or Compounds

[0134] These complexes can contain four types of ligands: monodentate ligands, bidentate ligands, tridentate ligands, and tetradentate ligands. The bonding between the ligand and the metal center in a metal complex typically involves the formal donation of one or more electron pairs from the donor atoms of the ligand. The donor atoms can be carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As), and selenium (Se).

[0135] In some forms, the ligand has the chemical structure shown in General Formula IV:

[0136]

[0137] Wherein:

[0138] L represents a chemical moiety containing one or more donor atoms, preferably one donor atom, for coordinating with the metal center of a metal complex. Exemplary chemical moieties include but are not limited to five-membered aromatic hydrocarbons and their derivatives, such as furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; six-membered aromatic hydrocarbons and their derivatives, such as benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene; Exemplary ligands also include but are not limited to halide ions, SCN - (donor atom: S), O-NO2 - (donor atom: O), N3 - 、O2 - 、S2 - 、H2O、O-NO - (donor atom: O), NCS - (donor atom: N), NH3, NO2 - (donor atom: N), N≡C - (donor atom: N), C≡N - (donor atom: C), CO (donor atom: C), R-C≡C - 、RO - 、RS - 、RSe - 、N=N=N-R、N≡C-R (donor atom: N), C≡N-R (donor atom: C), NR 1 R 2 R 3 、PR 1 R 2 R 3 and AsR 1 R 2 R 3 。

[0139] In certain forms of these ligands, R, R 1 、R 2 and R 3Independently: a hydrogen atom, a halogen atom, a sulfonic acid, an azide group, a cyanate group, an isocyanate group, a nitrate group, a nitrile group, an isonitrile group, a nitrosooxy group, a nitroso group, a nitro group, an aldehyde group, an acyl halide group, a carboxylic acid group, a carboxylic acid ester group, an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group;

[0140] A hydroxyl group, which optionally contains a substituent at the hydroxyl oxygen, where the substituent is an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group;

[0141] A thiol group, which optionally contains a substituent at the thiol sulfur, where the substituent is an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group;

[0142] A carbonate group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group;

[0143] An amino group, which optionally contains one or two substituents at the amino nitrogen, where the substituents are an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or a combination thereof;

[0144] An amide group, which optionally contains one or two substituents at the amide nitrogen, where the substituents are an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or a combination thereof;

[0145] An azo group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group;

[0146] An acyl group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group;

[0147] An ester group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group; a carbonate group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group; an ether group, which contains an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group; an aminooxy group, which optionally contains one or two substituents at the amino nitrogen, wherein the substituents are an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group or a combination thereof; or

[0148] a hydroxyamino group, which optionally contains one or two substituents, wherein the substituents are an optionally substituted alkyl group, an optionally substituted heteroalkyl group, an optionally substituted alkenyl group, an optionally substituted heteroalkenyl group, an optionally substituted alkynyl group, an optionally substituted heteroalkynyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group or a combination thereof,

[0149] In some forms, R, R 1 , R 2 , R 3 and their organic substituents are optional and independently substituted by one or more groups, wherein each such group is independently:

[0150] a halogen atom, an alkyl group, a heteroalkyl group, an alkenyl group, a heteroalkenyl group, an alkynyl group, a heteroalkynyl group, an aryl group, a heteroaryl group, -OH, -SH, -NH2, -N3, -OCN, -NCO, -ONO2, -CN, -NC, -ONO, -CONH2, -NO, -NO2, -ONH2, -SCN, -NCS, -CF3, -CH2CF3, -CH2Cl, -COF, -COBr, -COOH, -S3H, -CH2SO2CH3, -PO3H2, -OPO3H2, -P(═O)(OR G1’ )(OR G2’ ), -OP(═O)(OR G1’ )(OR G2’ ), -BR G1’ (OR G2’ ), -B(OR G1’ )(OR G2’ ) or -G’R G1’ , wherein -G’ is -O-, -S-, -NR G2’-, -C(═O)O-, -C(═O)-, -S(═O)-, -SO2-, -C(═O)O-, -C(═O)NR G2’ -, -NR G2’ C(O)-, -NR G2’ C(═O)NR G3’ -, -C(═S)-, -C(═S)S-, -SC(═S)-, -SC(═S)S-, -C(═NR G2’ )-, -C(═NR G2’ )O-, -C(═NR G2’ )R G3’ -, -OC(═NR G2’ )-, -NR G2’ C(═NR G3’ )-, -NR G2’ SO2-, -C(═NR G2’ )NR G’ )-, -OC(═NR G2’ )-, -NR G2’ SO2NR G3’ -, -NR G2’ C(═S)-, -SC(═S)NR G2’ -, -NR G2’ C(═S)S-, -NR G2’ C(═S)NR G3’ -, -SC(═NR G2’ )-, -C(═S)NR G2’ -, -OC(═S)NR G2’ -, -NR G2’ C(═S)O-, -SC(═O)NR G2’ -, -NR G2’ C(═O)S-, -C(═O)S-, -SC(═O)-, -SC(═O)S-, -C(═S)O-, -OC(═S)-, -OC(═S)O-, -SO2NR G2’ -, -BR G2’ - or -PR G2’ -.

[0151] Wherein each occurrence of R G1’ , R G2’ and R G3’ is independently a hydrogen atom, a halogen atom, an alkyl group, a heteroalkyl group, an alkenyl group, a heteroalkenyl group, an alkynyl group, a heteroalkynyl group, an aryl group or a heteroaryl group.

[0152] The linking group represents a structure that facilitates an optional covalent linking moiety between the ligand and the amino acid / positively charged moiety. The linking group can be selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives, and combinations thereof.

[0153] AA is selected from amino acids having the following structures, or their derivatives, or combinations of amino acids and / or their derivatives.

[0154]

[0155] Exemplary structures of the ligand in Formula IV are shown below, using histidine, one of these amino acids, as an example. Histidine can be replaced by other amino acids or their derivatives, or combinations of amino acids and / or their derivatives.

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171] P represents a structure containing a positive charge. The positively charged structure can be selected from, but is not limited to, substituted and unsubstituted amines, ammonium, pyridinium, pyrrodinium, phosphonium, imidazolium, sulfonium, and their derivatives. Exemplary structures of the ligands in Formula IV are shown below:

[0172]

[0173] C. Exemplary Formulas and Chemical Structures of Compounds

[0174] Preferably, the metal complex has a square planar or partially planar geometric configuration. The structures can be classified according to the type of ligand: monodentate ligand, bidentate ligand, tridentate ligand, and tetradentate ligand. In some forms, the metal complex has a chemical structure shown by General Formula I:

[0175]

[0176] Wherein:

[0177] (a) M is a metal atom (also known as the metal center). It can be Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), and Cu(III).

[0178] (b) L1, L2, L3, L4 represent ligands. Each ligand can provide a donor atom for coordination with the metal center.

[0179] (c) n+ / - is the number of charges (positive or negative) carried by the metal complex. n can be zero or a positive integer, such as 1, 2, 3, 4, and 5.

[0180] (d) X is a counterion used to make the compound charge-neutral.

[0181] When X m- / + is an anion, for example, X m- , it can be selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO42- ), phosphate (PO4 3- ) and its derivatives.

[0182] When X m- / + is a cation, such as X m+ , it can be selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ), quaternary ammonium cation, and its derivatives.

[0183] (e) m- / + is the number of charges (positive or negative) carried by the counterion. X should carry a charge opposite to that of the metal complex. m can be zero or a positive integer, such as 1, 2, 3, 4, and 5.

[0184] (f) represents the stoichiometry of the counterion in the formula.

[0185] (g) The four dashed lines represent an optional independent covalent connection between two ligands, an optional independent fusion of the ring portions from two ligands, or a combination thereof.

[0186] Examples of Formula I are shown below:

[0187]

[0188] Wherein:

[0189] (a) The lines represent an optional connection between two ligands. They also represent an optional fusion of rings from different ligands.

[0190] In some forms, L1, L2, L3, and L4 are independently selected from C6-C 50 arene or C3-C 50 heteroarene, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN- (where S is the donor atom), O-NO2 - (where O is the donor atom), N3 - 、O2 - 、S2 - , H2O, O-NO - (where O is the donor atom), NCS - (where N is the donor atom), NH3, NO2 - (where N is the donor atom), N≡C - , CO (where C is the donor atom), RC≡C - ,RO - , RS - 、RSe - 、N=N=NR、N≡CR (where N is the donor atom), C≡NR (where C is the donor atom), NR 1 R 2 R 3 , PR 1 R 2 R 3 and AsR 1 R 2 R 3 . (R, R 1 , R 2 and R 3 As defined above). For example, R, R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 Alkyl, C2~C 30 Alkenyl, C2~C 30 Alkynyl, C3~C 30 Aryl, C3~C 30 Heteroaryl, C1~C 30 Alkoxy, C3~C 30 Aryloxy, C3~C 30 Arylthio, C1~C 30 Alkylthio, C2~C 30 Carbonyl, C1~C 30 Carboxyl, amino, amido or polyaryl (containing fused or non-fused ring moieties).

[0191] In some forms, L1, L2, and L3 can be independently selected from C6 to C 50 Aromatics or C3~C 50In heteroarenes. The structures include but are not limited to five-membered aromatic hydrocarbons and their derivatives, such as furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; six-membered aromatic hydrocarbons and their derivatives, such as benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine.

[0192] In some forms, L4 can be selected from five-membered aromatic hydrocarbons and their derivatives, such as furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; six-membered aromatic hydrocarbons and their derivatives, such as benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine; carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN - , NO3 - , N3 - , O2 - , S2 - , H2O, NO2 - , NCS - , NH3, NO2 - , CN - , CO, R-C≡C - , RO - , RS - , RSe - and derivatives (where R is as defined above). For example, R is selected from substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 arylthio, C1-C 30 alkylthio, C2-C 30 carbonyl, C1-C 30 carboxyl, amino, amido or polyaryl (containing fused or unfused ring moieties).

[0193] In some forms, L1 and L2 are linked by a covalent bond, a fusion of ring portions from two ligands, or a combination thereof. In some forms, L2 and L3 are further linked by a covalent bond, a fusion of ring portions from two ligands, or a combination thereof. In some forms, L1 and L4 are further linked by a covalent bond, a fusion of ring portions from two ligands, or a combination thereof. In some forms, L3 and L4 are further linked by a covalent bond, a fusion of ring portions from two ligands, or a combination thereof.

[0194] In some forms, the metal complex has a chemical structure as shown in General Formula II:

[0195]

[0196] Where:

[0197] (a) M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II).

[0198] (b) L5 and L6 represent ligands. Each ligand can provide a donor atom for coordination with the metal center.

[0199] In some forms, the metal complex has a chemical structure as shown in General Formula III, which exhibits a trigonal planar geometry:

[0200]

[0201] Where:

[0202] (a) L7, L8, L9 represent ligands. Each ligand can provide a donor atom for coordination with the metal center.

[0203] Examples of Formula III are shown below:

[0204]

[0205] Where:

[0206] (a) The lines represent optional connections between two ligands. They also represent optional fusions of rings from different ligands, or combinations thereof.

[0207] In some forms, the metal complex has a chemical structure as shown in General Formula V:

[0208]

[0209] Where:

[0210] (a) a, b, c, d are independently 0 or a positive integer, such as 1, and a + b + c + d > 0.

[0211] (b) The linking group represents a structure that facilitates an optional linking moiety between L and P / AA, where the linking group is preferably selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives, and their combinations.

[0212] (c) AA is selected from amino acids, their derivatives, or combinations of amino acids and / or their derivatives, and preferably AA is selected from:

[0213]

[0214] (d) P represents a structure containing a positive charge, preferably substituted and unsubstituted amines, ammonium, pyridinium cations, pyrrolidinium cations, phosphonium, imidazolium cations, sulfonium, and their derivatives.

[0215] In some forms, the metal complex is as described above, except that the metal complex has a chemical structure represented by General Formula VI:

[0216]

[0217] Wherein:

[0218] (a) e and f are independently 0 or a positive integer, such as 1, and e + f > 0.

[0219] In some forms, the metal complex is as described above, except that the metal complex has a chemical structure represented by General Formula VII:

[0220]

[0221] Wherein:

[0222] (a) g, h, and i are independently 0 or a positive integer, such as 1, and g + h + i > 0.

[0223] Examples of metal complexes designed as Formulas I, II, III, V, VI, and VII are shown below.

[0224]

[0225] Wherein:

[0226] (a) M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0227] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0228] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0229] (d) represents the stoichiometry of the counterion in the formula.

[0230]

[0231] Where:

[0232] (a) M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0233] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0234] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0235] (d) represents the stoichiometry of the counterion in the formula.

[0236]

[0237] Where:

[0238] (a) M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0239] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0240] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0241] (d) represents the stoichiometry of the counterion in the formula.

[0242]

[0243] Where:

[0244] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0245] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0246] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0247] (d) represents the stoichiometry of the counterion in the formula.

[0248]

[0249] Where:

[0250] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0251] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0252] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0253] (d) represents the stoichiometry of the counterion in the formula.

[0254]

[0255] Where:

[0256] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0257] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0258] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0259] (d) represents the stoichiometry of the counterion in the formula.

[0260]

[0261] Where:

[0262] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III).

[0263] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0264] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0265] (d) represents the stoichiometry of the counterion in the formula.

[0266]

[0267] Where:

[0268] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III).

[0269] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0270] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0271] (d) represents the stoichiometry of the counterion in the formula.

[0272]

[0273] Where:

[0274] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III).

[0275] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0276] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0277] (d) represents the stoichiometry of the counterion in the formula.

[0278]

[0279] Wherein:

[0280] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0281] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0282] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0283] (d) represents the stoichiometry of the counterion in the formula.

[0284]

[0285] Wherein:

[0286] (a) M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III).

[0287] (b) n represents the charge number of the metal complex in the formula, where n is zero or a positive integer.

[0288] (c) X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n.

[0289] (d) represents the stoichiometry of the counterion in the formula.

[0290] D. Mixtures and Compositions

[0291] Also disclosed are mixtures containing a series of compounds. The mixtures can be used for detecting and / or imaging analytes and / or differentiating cancer cells from normal cells, and / or screening the efficacy of inhibitors. For example, the analyte can be sialic acid, polysialic acid, glycans and cancer cells.

[0292] In some forms, the chemical structure of the compound can be represented by Formula I, II, III, IV, V, VI or VII.

[0293] In some forms, the photophysical properties of the compound exhibit significant changes upon addition of sialic acid, polysialic acid, glycan, or cancer cells; in some embodiments, the compound will be undisturbed in the presence of other monosaccharides; in some embodiments, the compound can image sialic acid on the surface of cancer cells and exhibit different luminescence signals on the surfaces of cancer cells and normal cells, enabling the differentiation of different types of cells. In some forms, the compound can be used for the early diagnosis of cancer and / or diseases and anti-cancer therapies.

[0294] E. Kit

[0295] The kit may comprise the above-mentioned compounds, mixtures, and compositions.

[0296] The kit comprises one or more containers, one or more of the disclosed compounds, mixtures, and compositions. The kit contains other components such as compounds, solutions, materials, and carriers. The materials of the carriers will not interfere with the effectiveness of the disclosed compounds. The kit may include instructions for use.

[0297] The kit can be used for detecting analytes and / or differentiating cancer cells from normal cells and screening the efficacy of inhibitors.

[0298] The kit may further comprise one or more positive controls and negative controls.

[0299] III. Preparation Methods and Their Reagents

[0300] The compounds of Formula I, II, III, IV, V, VI, or VII can be easily synthesized using techniques commonly known to synthetic organic and inorganic chemists. Exemplary methods for synthesizing a specific compound of Formula I (i.e., Complex 1-Pt) are described in the disclosed examples.

[0301] IV. Methods of Use

[0302] The disclosed compounds can be used in methods for sensing and / or imaging analytes, differentiating cancer cells from normal cells, detecting or diagnosing cancer and / or diseases, and screening and testing inhibitors.

[0303] In some forms, the analyte can be glycan (such as sialic acid, polysialic acid, etc.) and cancer cells.

[0304] The method for sensing and / or imaging an analyte in a sample (preferably a biological sample) can be: (1) adding one or more compounds to a container and then adding the sample, or vice versa, and then mixing the complex with the sample; (2) measuring the change in the photophysical properties of the complex to check whether the complex undergoes assembly / decomposition, which is induced by combining the sample and one or more compounds in the container. The change in the photophysical properties indicates the presence of the analyte of interest.

[0305] The method for testing the efficacy of an inhibitor in removing an analyte or inhibiting the generation of an analyte may be as follows: (1) Mix a compound disclosed herein, such as a compound of Formula I, II, and / or III, with a sample (preferably a biological sample) treated with an inhibitor, and then mix the compound with a corresponding sample (preferably a corresponding biological sample) not treated with the inhibitor; (2) Measure the change in the photophysical properties of the complex to check whether the complex undergoes assembly / disassembly, which is induced by combining the sample and one or more compounds. The change in the photophysical properties indicates the efficacy of the inhibitor. A weak inhibitor does not significantly reduce the level of sialic acid, resulting in a relatively high concentration of sialic acid on the surface of cancer cells. Such a high level of sialic acid can still induce self-assembly and aggregation, resulting in a drastic change in the photophysical properties. On the contrary, a potent inhibitor that promotes the reduction of sialic acid on the cell surface can prevent the self-assembly and aggregation of the compound and even cause the disaggregation of the compound. The obvious change in the photophysical properties caused by using inhibitors with different efficiencies can be used to evaluate the efficiency of the inhibitor. This can be used to screen for highly efficient inhibitors for therapy or other applications. The kit is not limited to a solution kit for spectroscopic measurement or observing color change or luminescence change in the solution state, but can also be modified or extended to an indicator test on a solid matrix indicator board or indicator paper.

[0306] A. Sensing or visualizing sialic acid, polysialic acid, glycan, or cancer cells.

[0307] Methods for detecting and / or imaging glycans (such as sialic acid, polysialic acid, etc.) and cancer cells are also disclosed. The method may be as follows: (1) Add one or more of the disclosed compounds to a container, then add a sample (preferably a biological sample), and vice versa, and then mix the compound with the sample; (2) Measure the change in the photophysical properties (such as color, absorbance, luminescence intensity, circular dichroism, circularly polarized luminescence, or a combination thereof) of the complex to check whether the complex undergoes assembly / disassembly, which is induced by combining the sample and one or more compounds in the container. The change in the photophysical properties indicates the change in the self-assembly behavior of the complex, indicating the presence of sialic acid, polysialic acid, glycan, or cancer cells in the sample.

[0308] According to the type of photophysical property, the measurement method may be luminescence emission measurement, ultraviolet-visible light absorption measurement, luminescence lifetime measurement, circular dichroism, circularly polarized luminescence, or a combination thereof.

[0309] For example, the detection of polysialic acid can be achieved by Figure 5The luminescence measurement shown in [reference] is carried out. After adding polysialic acid, an increase in the degree of self-assembly and / or aggregation of the metal complex can be indicated by an increase or growth of the emission band. The metal complex can bind to polysialic acid through electrostatic interactions and hydrogen bonds, resulting in the supramolecular self-assembly of the metal complex. Changes in the color and / or luminescence of the metal complex can be used as an indicator of polysialic acid.

[0310] The detection can be carried out using a non-imaging spectrometer in a cuvette or a multi-well plate. The detection can also be carried out using an imaging spectrometer in a cell culture dish or a multi-well plate. The kit is not limited to a solution kit for spectroscopic measurement or observing color changes or luminescence changes in the solution state, but can also be modified or extended to an indicator test on a solid matrix indicator plate or indicator paper.

[0311] B. Distinguishing cancer cells from normal cells

[0312] A method for distinguishing cancer cells from normal cells is also disclosed. The method can be: (1) mixing one or more compounds with a sample (preferably a biological sample), (2) imaging the change in the photophysical properties of the complex, which is related to the change in the degree of supramolecular self-assembly of the complex. The change in photophysical properties indicates the presence of sialic acid on the cell surface. A high level of sialic acid on the surface of cancer cells can facilitate the distinction of cancer cells and the detection and / or diagnosis of cancer / tumor and / or disease, and be used for image-guided surgery. The number of sialic acid molecules on the cell surface of cancer cells can range from 10 4 ~10 11 、10 5 ~10 11 、10 6 ~10 11 or 10 7 ~10 11 molecules, especially 10 7 ~10 11 molecules, which can be regarded as a high level. The reported luminescence measurements have reported a higher level of sialic acid in cancer cells compared to normal cells. The high density of these sialic acids leads to the self-assembly and aggregation of the compounds targeting them in cancer cells (Wang, et al., Anal. Chem., 2017, 89, 538 - 543; Xu, et al., Talanta, 2020, 209, 120579).

[0313] C. Screening inhibitors against sialic acid, polysialic acid and glycan

[0314] Also disclosed are methods for detecting the efficacy of an inhibitor in removing an analyte or inhibiting the generation of an analyte. It can be: (1) mixing one or more compounds of the present disclosure with an inhibitor-treated sample (preferably a biological sample), and then mixing the compound with the corresponding untreated sample (preferably the corresponding biological sample) as a control group; (2) measuring changes in the photophysical properties of the complex to check whether the degree of supramolecular self-assembly of the complex changes. Changes in photophysical properties indicate changes in the self-assembly behavior of the complex, thus indicating the efficacy of the inhibitor. This can be used to screen for useful inhibitors to remove sialic acid, which can be used in anti-cancer therapies. The kit is not limited to a solution kit for spectroscopic measurement or observing color changes or luminescence changes in the solution state, but can also be modified or extended to an indicator test on a solid matrix indicator board or indicator paper.

[0315] D. Combinatorial use

[0316] Also disclosed is the combinatorial use of more than one disclosed compound. Mixtures containing different compounds can exhibit different specificities for various glycans, including sialic acid, polysialic acid, etc. Different changes in the photophysical properties of different compounds in the mixture can be used to sense different components in a sample (preferably a biological sample). In addition, the mixture can be used for imaging or visualization, and / or monitoring the levels of glycans such as sialic acid, polysialic acid, etc.

[0317] E. Sample

[0318] In some forms, the sample (preferably a biological sample) contains glycans such as sialic acid, polysialic acid, and / or other monosaccharides, etc. The sample can be a body fluid (such as blood, plasma, serum), cells (such as eukaryotic cells, which are optionally selected from 3T3 cells, HeLa cells, HepG2 cells, MCF7 cells, HEK293T cells, Chinese hamster ovary (CHO) cells, and other cells), tissues (such as brain tissue, heart tissue, liver tissue, kidney tissue, spleen tissue, lung tissue, etc.), and animals.

[0319] The disclosed compositions and methods can be further understood through the following paragraphs.

[0320] 1. A compound for detecting and / or imaging an analyte, wherein the compound is d 8 or d 10 a metal complex or a salt thereof, including:

[0321] (a) A metal atom (also known as a metal center) having a coordination number of 2, 3, or 4, the metal atom being selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), Cu(III), Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II); and

[0322] (b) One or more ligands having donor atoms, the donor atoms independently selected from carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As), and selenium (Se),

[0323] wherein the metal complex binds to an analyte, and the binding of the metal complex to the analyte induces supramolecular self-assembly and / or aggregation of the metal complex through non-covalent metal-metal and / or π-π interactions.

[0324] 2. The compound of paragraph 1, wherein the compound has the structure of formula I:

[0325]

[0326] wherein:

[0327] (a) M is a metal atom (also called a metal center). It can be Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), and Cu(III);

[0328] (b) L1, L2, L3, L4 represent ligands. Each ligand can provide a donor atom for coordination with the metal center;

[0329] (c) n+ / - is the number of charges (positive or negative) carried by the metal complex, where n can be zero or a positive integer, such as 1, 2, 3, 4, and 5;

[0330] (d) X is a counterion used to render the compound charge-neutral. When X m- / + is an anion, for example, X m- can be selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO42- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and its derivatives. When X m- / + is a cation, for example X m+ , it may be selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ), quaternary ammonium cation, and its derivatives;

[0331] (e) m- / + is the number of charges (positive or negative) carried by the counterion. X should carry a charge opposite to that of the metal complex. m can be zero or a positive integer, such as 1, 2, 3, 4, and 5;

[0332] (f) represents the stoichiometry of the counterion n in the formula; and

[0333] (g) The four dashed lines represent an optional independent covalent connection between two ligands, an optional independent fusion of the ring portions from two ligands, or a combination thereof.

[0334] 3. The compound of paragraph 2, wherein L1, L2, L3, and L4 are independently selected from C6-C 50 arene or C3-C 50 heteroarene, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene; halides, alkylamines, arylamines, alkylphosphines, arylphosphines, alkylarsines, arylarsines, SCN - (where S is the donor atom), O-NO2 - (where O is the donor atom), N3 - , O2 - , S2 - , H2O, O-NO - (where O is the donor atom), NCS - (where N is the donor atom), NH3, NO2- (where N is the donor atom), N≡C - , CO (where C is the donor atom), R-C≡C - , RO - , RS - , RSe - , N=N=N-R, N≡C-R (where N is the donor atom), C≡N-R (where C is the donor atom), NR 1 R 2 R 3 , PR 1 R 2 R 3 and AsR 1 R 2 R 3 . (R, R 1 , R 2 and R 3 are defined as above). For example, R, R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 arylthio, C1-C 30 alkylthio, C2-C 30 carbonyl, C1-C 30 carboxyl, amino, amido or polyaryl (containing fused or unfused ring moieties).

[0335] 4. A compound according to paragraph 2 or paragraph 3, wherein L1 and L2 are linked by a covalent bond, fusion of ring moieties from two ligands, or a combination thereof.

[0336] 5. A compound according to paragraph 1, wherein the compound has the structure of formula II:

[0337]

[0338] wherein:

[0339] (a) M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II) and Hg(II); and

[0340] (b) L5 and L6 represent ligands. Each ligand can provide a donor atom for coordination with the metal center.

[0341] 6. The compound of paragraph 1, wherein the compound has the structure of formula III:

[0342]

[0343] Wherein:

[0344] (a) L7, L8, L9 represent ligands. Each ligand can provide a donor atom for coordination with the metal center.

[0345] 7. The compound of any one of paragraphs 1 - 6, wherein the ligand has the structure of formula IV:

[0346]

[0347] Wherein:

[0348] (a) L represents a chemical moiety containing one or more donor atoms, preferably one donor atom, for coordination with the metal center of the metal complex;

[0349] (b) The linker represents a structure that facilitates an optional covalent linking moiety between L and the amino acid / positively charged structure;

[0350] (c) AA represents an amino acid, or its derivative, or a combination of amino acids and / or their derivatives; and

[0351] (c) P represents a positively charged structure, preferably substituted and unsubstituted amines, ammonium, pyridinium, pyrrolidinium, phosphonium, imidazolium, sulfonium and their derivatives.

[0352] 8. The compound of any one of paragraphs 1 - 7, wherein the compound has the structure of formula V:

[0353]

[0354] Wherein:

[0355] (a) M is a metal center selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III) and Cu(III);

[0356] (b) L1, L2, L3 and L4 represent one or more coordinating ligands, wherein each ligand can provide at least one donor atom for coordination with the metal center;

[0357] (c) n+ / − is the charged state of the compound, where n is zero or a positive integer such as 1, 2, 3, 4 and 5;

[0358] (d) X is a counterion for rendering the compound charge-neutral, wherein when X m- / + is an anion, denoted as X m- when, X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and their derivatives, wherein when X m- / + is a cation, denoted as X m+ when, X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cations and their derivatives;

[0359] (e) m- / + is the charged state of the counterion, where m is zero or a positive integer such as 1, 2, 3, 4 and 5, where m = n or m ≠ n;

[0360] (f) represents the stoichiometry of the counterion in Formula V;

[0361] (g) The four dashed lines represent an optional independent covalent connection between two ligands, an optional independent fusion of the ring portions from two ligands, or a combination thereof.

[0362] (h) L1, L2, L3 and L4 are independently selected from C6-C 50 arene or C3-C 50Heteroaromatic hydrocarbons, such as five-membered aromatic hydrocarbons and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered aromatic hydrocarbons and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine , 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2′-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN - (where S is the donor atom), O-NO2 - (where O is the donor atom), N3 - 、O2 - 、S2 - , H2O, O-NO - (where O is the donor atom), NCS - (where N is the donor atom), NH3, NO2 - (where N is the donor atom), N≡C - , CO (where C is the donor atom), RC≡C - ,RO - , RS - 、RSe - 、N=N=NR、N≡CR (where N is the donor atom), C≡NR (where C is the donor atom), NR 1 R 2 R 3 , PR 1 R 2 R 3 and AsR 1 R 2 R 3 . (R, R 1 , R 2 and R 3 As defined above). For example, R, R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 Alkyl, C2~C 30 Alkenyl, C2~C 30 Alkynyl, C3~C 30 Aryl, C3~C 30 Heteroaryl, C1~C 30 Alkoxy, C3~C 30 Aryloxy, C3~C 30Arylthio group, C1-C 30 Alkylthio group, C2-C 30 Carbonyl group, C1-C 30 Carboxyl group, amino group, amide group or polyaryl group (containing fused or unfused ring moieties).

[0363] (i) a, b, c, and d are independently 0 or a positive integer, such as 1, and a + b + c + d > 0;

[0364] (j) The linking group represents a structure that facilitates an optional linking moiety between L and P / AA, where the linking group is preferably selected from unsubstituted and substituted alkyl groups, unsubstituted and substituted heteroalkyl groups, unsubstituted and substituted alkenyl groups, unsubstituted and substituted heteroalkenyl groups, unsubstituted and substituted alkynyl groups, unsubstituted and substituted heteroalkynyl groups, unsubstituted and substituted aryl groups, unsubstituted and substituted heteroaryl groups, unsubstituted and substituted sulfonyl groups, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy groups, unsubstituted and substituted hydroxyamino groups, and their derivatives, and their combinations.

[0365] (k) AA is selected from amino acids, their derivatives, or a combination of amino acids and / or their derivatives, preferably AA is selected from:

[0366] And

[0367] (l) P represents a structure containing a positive charge, preferably a substituted and unsubstituted amine, ammonium, pyridinium cation, pyrrolidinium cation, phosphonium, imidazolium cation, sulfonium, and their derivatives.

[0368] 9. A compound according to any one of the preceding paragraphs, wherein the compound has the structure of formula VI:

[0369]

[0370] Wherein:

[0371] (a) M' is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II);

[0372] (b) L5 and L6 represent one or more coordinating ligands, where each ligand can provide at least one donor atom for coordination with the metal center; and

[0373] (c) e and f are independently 0 or a positive integer, such as 1, and e + f > 0.

[0374] 10. The compound of any one of the preceding paragraphs, wherein the compound has the structure of Formula VII:

[0375]

[0376] Wherein:

[0377] (a) L7, L8, and L9 represent one or more coordinating ligands, where each ligand can provide at least one donor atom for coordination with the metal center; and

[0378] (b) g, h, and i are independently 0 or a positive integer, such as 1, and g + h + i > 0.

[0379] 11. The compound of any one of the preceding paragraphs, wherein the metal complex binds to the analyte through non-covalent interactions, and the non-covalent interactions include electrostatic interactions, hydrogen bond interactions, hydrophobic interactions, or a combination thereof.

[0380] 12. The compound of any one of the preceding paragraphs, wherein the metal complex has a planar structure or a partially planar structure.

[0381] 13. The compound of any one of the preceding paragraphs, wherein the aggregation and supramolecular self-assembly of the metal complex cause one or more changes in the photophysical properties of the metal complex.

[0382] 14. The compound of paragraph 13, wherein one or more changes in the photophysical properties include changes in optical absorbance, luminescence, or a combination thereof.

[0383] 15. The compound of paragraph 14, wherein the change in luminescence includes an increase in luminescence quantum yield and / or emission intensity, and / or a shift in emission energy or wavelength.

[0384] 16. The compound of any one of the preceding paragraphs, wherein the compound is selected from:

[0385]

[0386] Wherein M represents the metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, m = n or m ≠ n. Represents the stoichiometry of the counterion in the formula;

[0387]

[0388] Where M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0389]

[0390] Where M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0391]

[0392] Where M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0393]

[0394] Where M represents a metal center, which can be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0395]

[0396] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0397]

[0398] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0399]

[0400] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0401]

[0402] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0403]

[0404] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula;

[0405]

[0406] Wherein M represents a metal center, which may be selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III). n represents the charge number of the metal complex in the formula, where n is zero or a positive integer. X represents a counterion for charge neutrality, where n is zero or a positive integer, and m = n or m ≠ n. represents the stoichiometry of the counterion in the formula.

[0407] 17. A compound according to any of the preceding paragraphs, wherein the analyte can be a glycan such as sialic acid, polysialic acid, etc., or a cancer cell.

[0408] 18. A method for detecting an analyte in a sample (preferably a biological sample), the method comprising: (a) combining a compound according to any of the preceding paragraphs with the sample, (b) detecting a change in the photophysical properties of the metal complex, wherein a change in the photophysical properties of the metal complex indicates the presence of aggregation and supramolecular self-assembly of the metal complex, and the presence of aggregation and supramolecular self-assembly of the metal complex indicates the presence of the analyte in the sample.

[0409] 19. The method of paragraph 18, wherein the analyte is selected from glycans such as sialic acid, polysialic acid, etc., or cancer cells.

[0410] 20. The method of paragraph 18 or paragraph 19, wherein the sample comprises a human or non-human animal body fluid, a human or non-human animal tissue, or a combination thereof.

[0411] 21. A method for testing the efficacy of an inhibitor in removing sialic acid from the cell surface, the method comprising:

[0412] (a) combining a compound according to any of the preceding paragraphs with an inhibitor-treated sample containing a protein or peptide, and separately with the corresponding untreated sample containing a protein or peptide; and

[0413] (b) comparing the photophysical properties of the metal complex between the inhibitor-treated sample and the corresponding untreated sample;

[0414] The magnitude of the difference in the photophysical properties of the metal complex between two samples represents the degree of change in the aggregation and supramolecular self-assembly state of the metal complex, and the degree of change in the aggregation and supramolecular self-assembly state of the metal complex represents the efficacy of the inhibitor.

[0415] 22. A method for imaging an analyte in a sample, the method comprising:

[0416] (a) combining a compound of any one of the preceding paragraphs with the sample under conditions that permit binding of the metal complex of the compound to the analyte and subsequent aggregation and supramolecular self-assembly of the metal complex, wherein aggregation and supramolecular self-assembly of the metal complex result in a change in the photophysical properties of the metal complex; and

[0417] (b) imaging the analyte based on one or more photophysical properties characteristic of the metal complex after aggregation and supramolecular self-assembly.

[0418] 23. The method of paragraph 22, wherein the analyte is selected from glycans such as sialic acid, polysialic acid, etc., or cancer cells.

[0419] 24. The method of paragraph 22 or paragraph 23, wherein the sample contains eukaryotic cells optionally selected from 3T3 cells, A549 cells, Chinese hamster ovary (CHO) cells, HEK293 cells, HeLa cells, HepG2 cells, and HT1080 cells.

[0420] 25. A kit comprising one or more compounds of any one of the preceding paragraphs in one or more containers and optionally instructions for use, preferably wherein the kit is for detecting and / or imaging an analyte.

[0421] 26. The kit of paragraph 25, wherein the analyte is selected from glycans such as sialic acid, polysialic acid, etc., or cancer cells.

[0422] 27. The kit of paragraph 25 or paragraph 26, which further comprises a carrier.

[0423] 28. The kit of any one of the preceding paragraphs, wherein the presence of the analyte induces aggregation and supramolecular self-assembly of the metal complex thereon after binding, and the aggregation and supramolecular self-assembly of the metal complex can be detected by a change in the photophysical properties of the metal complex.

[0424] The methods, compounds, and compositions described herein are further illustrated in the following examples, which are provided by way of illustration and are not intended to be limiting. It will be understood that variations in the proportions of the components shown and substitutions of elements will be apparent to those skilled in the art and are within the scope of the disclosed form. Unless otherwise indicated, all parts or amounts are by weight.

[0425] Example

[0426] Example 1: Synthesis and Characterization of Complex 1-Pt

[0427] Materials and Methods

[0428] Complex 1-Pt was prepared as follows: [Pt{tpy-(C6H4CH2NMe3-4)-4'}Cl](PF6)2 (0.12 g, 0.17 mmol), triethylamine (1 mL), ligand HHIS (0.15 g, 0.51 mmol) and CuI (catalytic amount) were stirred in degassed DMF (6 mL) at room temperature under nitrogen. The precipitate obtained after pouring the mixture into diethyl ether was collected by centrifuge and then recrystallized by diffusing diethyl ether vapor into the methanol-acetonitrile solution of the solid to obtain a dark brown solid. Then the final water-soluble complex was prepared by salt metathesis reaction with LiCl. The product obtained was a dark brown solid.

[0429] Proton nuclear magnetic resonance ( 1 1H NMR) spectra were recorded on a Bruker AVANCE 500 Fourier transform NMR spectrometer (500 MHz) using tetramethylsilane as an internal standard. Negative fast atom bombardment (FAB) mass spectra were recorded on a Thermo Fisher Scientific DFS high-resolution sector field mass spectrometer. Elemental analysis was performed on a Thermo Fisher Scientific Flash EA 1112 elemental analyzer at the Institute of Chemistry, Chinese Academy of Sciences.

[0430] Results

[0431] (i) Characterization of Complex 1-Pt

[0432] Yield: 0.036 g (35%). 1 1H NMR (500 MHz, DMSO-d6, 298 K, δ / ppm) δ 9.27 (d, J = 9.3 Hz, 2H, terpyridine H), 9.14 (s, 2H, terpyridine H), 8.92 (d, J = 8.9 Hz, 2H, terpyridine H), 8.92 (m, 1H, imidazole H), 8.63 (t, J = 8.6 Hz, 2H, terpyridine H), 8.36 (d, J = 8.4 Hz, 2H, phenyl H), 8.01 (t, 2H, J = 8.0 Hz, terpyridine H), 7.87 (m, 4H, phenyl H), 7.87 (m, 1H, imidazole H), 7.65 (m, 2H, phenyl H), 4.65 (s, 1H, -CH(NH)-), 4.65 (s, 2H, -CH2N +(CH3)3), 3.63 (s, 3H, -CH3), 3.11 (s, 9H, -CH2N + (CH3)3). HRMS (positive ion ESI) C 41 H 39 N7O3Pt calculated value m = 436.1377; measured value: 436.1368 [M - 2Cl] + . Elemental analysis C 41 H 39 N7O3Cl2Pt·2CH2Cl2·H2O calculated value: C, 45.60; H, 3.98; N, 8.66. Measured value: C 45.13, H 4.12, N 8.69.

[0433] Example 2: Photophysical Properties of Complex 1 - Pt

[0434] Materials and Methods

[0435] The photophysical properties of Complex 1 - Pt were measured at a concentration of 30 μM.

[0436] Results

[0437] The UV - visible spectrum of Complex 1 - Pt in aqueous solution at 298K shows a high - energy absorption band at 260 - 290 nm and a low - energy band at 440 - 470 nm ( Figure 3 ). The high - energy absorption band can be attributed to the ligand - internal π→π * transition of the terpyridine and alkynyl ligands. At the same time, the lower - energy absorption band is assigned as a mixture of metal - to - ligand charge transfer (MLCT) [dπ(Pt)→π * (tpy)] and ligand - to - ligand charge transfer (LLCT) [π(C≡C)→π * (tpy)] transitions.

[0438] After adding polysialic acid, an absorption shoulder band appears at 600 nm, which can be attributed to the metal - metal - to - ligand charge transfer (MMLCT) transition, demonstrating the self - assembly of the metal complex. The emission band at 760 nm is typical of the triplet metal - metal - to - ligand charge transfer ( 3 MMLCT) excited state.

[0439] Example 3: Detection of Polysialic Acid by UV - Visible and Emission Spectroscopy

[0440] Materials and Methods

[0441] Polysialic acid at different concentrations (0 - 90 μM) was added to a solution of complex 1-Pt (30 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0). At 25 °C, the ultraviolet-visible absorption spectra and emission spectra were recorded, with the increase in the concentration of polysialic acid. The emission spectra were recorded at an excitation wavelength of 530 nm.

[0442] Results

[0443] Figure 3 Showed the ultraviolet-visible spectra of complex 1-Pt and the gradual changes after the addition of increasing concentrations of polysialic acid (0 - 114 μM). The addition of polysialic acid (0 - 2 equivalents) to the aqueous buffer solution of complex 1-Pt led to a decrease in the low-energy band at 445 nm and a slight red shift, as well as a significant increase in the lower-energy absorption shoulder band at 600 nm, which was due to the supramolecular self-assembly and aggregation of the metal complex.

[0444] Figure 4 Proved that the subsequent addition of polysialic acid (2 - 3.8 equivalents) had no effect on the absorption bands of complex 1-Pt, indicating that the binding might have reached equilibrium.

[0445] Figure 5 Showed the emission spectra of complex 1-Pt and the gradual changes after the addition of increasing concentrations of polysialic acid (0 - 90 μM). The addition of polysialic acid (0 - 3 equivalents) to the aqueous buffer solution of complex 1-Pt led to luminescence starting at 760 nm, which was due to the supramolecular self-assembly and aggregation of the metal complex.

[0446] Figure 6 Exhibited a significant increase in the emission band at 760 nm. The significant enhancement of the emission band indicated the formation of aggregates.

[0447] Example 4: High binding affinity of complex 1-Pt for polysialic acid

[0448] Materials and methods

[0449] To a solution of complex 1-Pt in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0), different concentrations of polysialic acid were added. The emission spectra were recorded at 25 °C at an excitation wavelength of 530 nm. The emission intensity at 800 nm was fitted using the Hill equation (see examples of similar data fitting in Donabedian et al., ACS Chem. Neurosci., 6, 1526 - 1535 (2015); Goutelle et al., Fundam. Clin. Pharmacol., 22, 633 - 648 (2008); and Gesztelyi et al., Arch. Hist. Exact Sci., 66, 427 - 438 (2012))

[0450]

[0451] where:

[0452] y represents the corrected emission intensity; x represents the concentration of polysialic acid; n represents the Hill coefficient, which can be used to represent the cooperativity of binding to polysialic acid; K d represents the apparent dissociation constant.

[0453] Results

[0454] The apparent dissociation constant between complex 1-Pt and polysialic acid was calculated to be 9.52×10 -9 M, demonstrating its high affinity for polysialic acid.

[0455] Example 5. Discrimination of polysialic acid and sialic acid by complex 1-Pt

[0456] Materials and methods

[0457] Sialic acid (Neu5Ac) at different concentrations (0 - 90 μM) was added to a solution of complex 1-Pt (30 μM) in an aqueous solution. At 25 °C, the emission spectra were recorded with the increase in the concentration of sialic acid. The emission spectra were recorded at an excitation wavelength of 530 nm.

[0458] Results

[0459] Figure 7 The emission spectra of complex 1-Pt and the gradual changes after the addition of increasing concentrations of polysialic acid (0 - 90 μM) are shown. Adding Neu5Ac (0 - 3 equivalents) to the aqueous buffer solution of complex 1-Pt resulted in a decrease in luminescence at 760 nm, which was due to the decomposition of the metal complex. The results indicate that the different response behaviors of complex 1-Pt to polysialic acid and sialic acid can cause different luminescence changes.

[0460] Example 6. The selectivity of Complex 1-Pt for polysialic acid is higher than that for other monosaccharides

[0461] Materials and Methods

[0462] Different monosaccharides (1, 5, 10 equivalents of mannose, glucose, lactose, sucrose, galactose) were separately mixed with Complex 1-Pt (30 μM) in Tris-HCl buffer (10 mM Tris, 10 mM NaCl, pH = 8.0). The emission spectra were recorded at 25 °C. The emission spectra were recorded at an excitation wavelength of 530 nm.

[0463] Results

[0464] Figure 8 The measured emission spectra of Complex 1-Pt after the addition of different monosaccharides (1, 5, 10 equivalents of mannose, glucose, lactose, sucrose, galactose) were shown to study the selectivity of Complex 1-Pt. The results showed that Complex 1-Pt did not exhibit an obvious spectral response to other monosaccharides, demonstrating that the presence of other monosaccharides did not affect the sensing ability of Complex 1-Pt for polysialic acid.

[0465] Example 7. Complex 1-Pt, Complex 9-Pt, and Complex 10-Pt can be used to visualize sialic acid on the surface of cancer cells.

[0466] Materials and Methods

[0467] HepG2 cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with a constant CO2 level maintained at 5%. HeLa cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with a constant CO2 level maintained at 5%. Then the cells were adhered to sterile coverslips in 35-mm cell culture dishes and cultured in a humidified incubator for 48 hours. After incubation, the cells were washed 3 times with PBS buffer.

[0468] In the time-dependent cell imaging experiment, Complex 1-Pt (10 μM) was added to the cell culture dishes, and the cells were incubated in the incubator for different times (0.5 h, 1 h, 2 h, 6 h, 8 h). Confocal imaging measurements were performed on a Leica TCS SPE confocal scanning microscope. Confocal images were obtained at an excitation wavelength of 405 nm, and the emission was collected at 700 - 800 nm using a 63× oil objective lens.

[0469] In the concentration-dependent cell imaging experiment, complexes 1-Pt (10 μM, 20 μM, 30 μM) were added to cell dishes, and the cells were incubated in an incubator for 0.5 h. Confocal imaging analysis was performed on a Leica TCS SPE confocal scanning microscope. Confocal images were obtained at an excitation wavelength of 405 nm, and the emission was collected at 700 - 800 nm using a 63× oil objective lens.

[0470] Results

[0471] Figures 10A - 10P show the time-dependent cell imaging experiment of complex 1-Pt. The accumulation of complex 1-Pt on the surface of cancer cells could be observed within 0.5 h.

[0472] Figures 9A - 9J show the concentration-dependent cell imaging experiment of complex 1-Pt. The luminescence signals of cells incubated with complexes 1-Pt at different concentrations (10 μM, 20 μM, 30 μM) were similar. Therefore, 10 μM was selected as the working concentration for better biocompatibility.

[0473] Figures 11A - 11C and 12A - 12C show that bright luminescence signals could be observed on the surface of HepG2 cells and HeLa cells after incubation with complex 1-Pt at 37 °C for 0.5 h. Figures 18A and 19A show that luminescence signals with relatively weak emission intensity could also be observed on the surface of HepG2 cells after incubation with complexes 9-Pt and 10-Pt.

[0474] Example 8. Distinguishing Cancer Cells from Normal Cells by Complexes 1-Pt, 9-Pt and 10-Pt

[0475] Materials and Methods

[0476] HepG2 cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with a constant CO2 level of 5%. HEK293T cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with a constant CO2 level of 5%. Then the cells were adhered to sterile cover slips in 35-mm cell culture dishes and cultured in a humidified incubator for 48 h. Then complex 1-Pt was added to the cell dishes, and the cells were incubated in the incubator for 0.5 h. Confocal imaging analysis was performed on a Leica TCS SPE confocal scanning microscope. Confocal images were obtained at an excitation wavelength of 405 nm using a 63× oil objective lens, and the emission was collected at 700 - 800 nm.

[0477] FITC-conjugated lectin was used to stain sialic acid on the surfaces of cancer cells and normal cells. Confocal images were obtained using a 63× oil objective lens. Luminescent confocal images were obtained for complex 1-Pt at an excitation wavelength of 405 nm and the emission was collected at 700 - 800 nm, while luminescent confocal images were obtained for FITC-conjugated lectin at an excitation wavelength of 488 nm and the emission was collected at 500 - 550 nm.

[0478] Results

[0479] Figures 14A - 14E show that on the surface of live HepG2 cells, complex 1-Pt exhibited a strong luminescence signal, while the FITC-conjugated lectin also exhibited a strong fluorescence signal. In addition, the colocalization coefficient between complex 1-Pt and the FITC-conjugated lectin was 0.87, confirming the ability of complex 1-Pt to stain sialic acid on the cell surface. However, complexes 1-Pt, 9-Pt, and 10-Pt showed no signal on the surface of live HEK293T cells (Figures 11D - 11F, 12D - 12F, 18B, and 19B). The bar graphs show that complex 1-Pt exhibited different emission signals on the surfaces of cancer cells (HeLa cells and HepG2 cells) and normal cells (HEK293T cells), while complexes 9-Pt and 10-Pt exhibited less distinct contrast signals (Figures 11G, 12G, 18C, and 19C). The results indicate that complexes 1-Pt, 9-Pt, and 10-Pt can distinguish cancer cells and normal cells through different luminescence signals, avoiding the possibility of false positive results. Among the three complexes, complex 1-Pt exhibited the best discrimination ability.

[0480] Example 9. Staining cell membranes with complex 1-Pt

[0481] Materials and methods

[0482] HepG2 cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with the CO2 level constantly maintained at 5%. The cells were then adhered to sterile coverslips in 35-mm cell culture dishes and cultured in the humidified incubator for 48 hours. Then, complex 1-Pt (10 μM) was added to the cell dishes, and the cells were incubated in the incubator for 0.5 h. A commercial deep red plasma membrane staining tracer (5 μg / mL) was used as the staining dye for cell membranes. Cell confocal imaging assays were performed on a Leica TCS SPE confocal scanning microscope. Confocal images were obtained using a 63× oil objective lens. For complex 1-Pt, luminescent confocal images were obtained at an excitation wavelength of 405 nm, and the emission was collected at 700 - 800 nm, while for the deep red plasma membrane staining tracer, luminescent confocal images were obtained at an excitation wavelength of 635 nm, and the emission was collected at 650 - 670 nm.

[0483] Results

[0484] Colocalization assays with a commercial membrane tracer have been performed using HepG2 cells to confirm the ability of complex 1-Pt to stain cell membranes. Figures 14A - 14E show that the membranes of HepG2 cells are strongly co-stained with complex 1-Pt and the membrane tracer.

[0485] Example 10. Visualization of changes in sialic acid levels after treatment with complex 1-Pt of neuraminidase

[0486] Materials and Methods

[0487] HepG2 cells were cultured in DMEM medium supplemented with 10% FBS at 37 °C in a humidified incubator with the CO2 level constantly maintained at 5%. The cells were then adhered to sterile coverslips in 35-mm cell culture dishes and cultured in the humidified incubator for 48 hours. Then, a neuraminidase solution (0.1 U / mL) was used to induce a decrease in sialic acid levels. Then, complex 1-Pt (10 μM) was added to the cell dishes, and the cells were incubated in the incubator for 0.5 h. Cell confocal imaging assays were performed on a Leica TCS SPE confocal scanning microscope. Confocal images were obtained using a 63× oil objective lens. For complex 1-Pt, luminescent confocal images were obtained at an excitation wavelength of 405 nm, and the emission was collected at 700 - 800 nm.

[0488] Results

[0489] Figures 15A - 15G show that complex 1-Pt exhibits a strong luminescence signal on the surface of live HepG2 cells without any treatment, while no luminescence signal is observed in live HepG2 cells treated with neuraminidase (0.1 U / mL). This result indicates that complex 1-Pt can visualize the change in the sialic acid luminescence signal on the cell surface, which can be used to screen inhibitors for removing sialic acid.

[0490] Example 11. Low cytotoxicity of complex 1-Pt

[0491] Materials and methods

[0492] HepG2 cells were adhered to a 96-well plate. Each well had approximately 10,000 cells. Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) (100 μL) was used as the culture medium, and the 96-well plate was placed in a humidified incubator at 37 °C (CO2 level: 5%). Different concentrations of complex 1-Pt (0.78, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 μM) were added, and the cells were incubated at 37 °C for 24 hours. After incubation, 10 μL of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) solution (5 mg / mL) was added to each well, and the plate was incubated at 37 °C for 3 hours. After removing the solution, DMSO (200 μL) was added to dissolve the precipitated formazan. Then, the absorbance of formazan at 570 nm was measured using a microplate absorbance reader. Cell viability was expressed as the percentage ratio of the absorbance of cells treated with complex 1-Pt to the absorbance of the control.

[0493] Results

[0494] Figure 16 The MTT cell viability assay was performed for 24 h to study the cytotoxicity of complex 1-Pt on HepG2 cells. The results show that complex 1-Pt has good biocompatibility and low cytotoxicity.

[0495] Example 12. Distinguishing cancer cells and normal cells by comparing complex 1-Pt with commercial dyes

[0496] Materials and methods

[0497] Live HEK293T cells were stained with complex 1-Pt (10 μM) for 0.5 h, then incubated with paraformaldehyde fixation solution for 15 min, and incubated with FITC-conjugated lectin (20 μg / mL) for 1 h.

[0498] Results

[0499] Figures 17A to 17D show confocal images of live HEK293T cells (as a normal cell line) incubated with complex 1-Pt and FITC-conjugated lectin. In the confocal image with emission collected at 700 - 800 nm in Figure 17A, no luminescence signal of complex 1-Pt was observed in the normal cells, while in the confocal image with emission collected at 500 - 550 nm in Figure 17B, the FITC-conjugated lectin was located on the cell membrane of the normal cell line.

[0500] These results and the results from Figures 13A - 13E, in which both complex 1-Pt and FITC-conjugated lectin showed similar localization in HepG2 cells as a cancer cell line in confocal images, indicate the ability of complex 1-Pt to stain only cancer cells and thus distinguish cancer cells from normal cells.

[0501] In clinical use, common probes based on traditional sensing methods are used, such as indocyanine green (ICG) and 5-aminolevulinic acid (5-ALA). Cancer cells are distinguished by the difference in fluorescence signal intensity, which is affected by strong background signals that interfere with the detection accuracy. Since normal cells are not stained by 1-Pt, compared with currently commercial probes, the strategy of the present disclosure accurately detects cancer cells with a low false positive rate.

[0502] For the kit for detecting sialic acid, the sialic acid quantification kit from SigmA-Aldrich can only measure the total sialic acid content from the amount of N-acetylneuraminic acid (free, or in glycoproteins, cell surface glycoproteins, polysialic acid, and capsular polysaccharides), while from the UV-visible and emission spectra provided in the data of the present disclosure, the disclosed compounds can more selectively detect polysialic acid or other sialic acid polymers. Therefore, this assay is superior to commercially available kits.

[0503] In summary, there is a significant amount of sialic acid on the surface of cancer cells, which ranges from an order of magnitude of 10 7 to 10 11 molecules per cell, contributing to the adhesion of cancer cells to vascular endothelium and helping to evade the recognition of the immune system (Narayanan, et al., Ann. Clin. Lab Sci., 1994, 24, 376 - 384). The malignant or metastatic phenotypes of different cancers can result in different amounts of sialic acid on the cell surface. For example, SMMC-7721 cells exhibit approximately 1.37×10 11 sialic acid molecules; (Wang, et al., Anal. Chem., 2017, 89, 538 - 543); while HeLa cells exhibit approximately 4.6×10 7One sialic acid molecule (Xu, et al., Talanta, 2020, 209, 120579). Different from current clinical probes such as ICG and 5-ALA, the compounds disclosed herein do not exhibit strong background signals due to high autofluorescence that interferes with detection accuracy. In addition, the compounds disclosed herein can specifically bind to the desired analyte through non-bonding interactions, especially electrostatic interactions and hydrogen bonds, thereby improving the selectivity and sensitivity to the analyte. In addition, the changes in photophysical properties caused by the supramolecular self-assembly of the complex after binding to the high density of sialic acid on the cancer cell surface facilitate tumor recognition, early diagnosis, and surgical guidance.

[0504] The experimental results significantly demonstrate the advantages and uniqueness of the compounds disclosed herein. Apparently, in aqueous solution, a significant enhancement in the luminescence performance of the metal complex was observed after the addition of polysialic acid, in sharp contrast to a slight decrease in luminescence performance after the addition of sialic acid monomers. These findings demonstrate the efficacy of the compounds disclosed herein. In cell imaging assays, distinct luminescence signals were observed on the surfaces of both cancer cells (HeLa cells and HepG2 cells) and normal cells (HEK293T cells), indicating applicability for early diagnosis and providing guidance for tumor resection surgery. Comparison with commercially available dyes shows successful staining on the cancer cell membrane and minimal background signal on the normal cell membrane.

[0505] Those skilled in the art will recognize or be able to ascertain using only routine experimentation many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

1. A compound comprising one or more metal centers having a d 8 or d 10 electronic configuration and one or more coordinating ligands, said coordinating ligands comprising one or more donor atoms, wherein: (a) The one or more metal centers have a coordination number of 2, 3, or 4 and are selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), Cu(III), Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), Hg(II), and combinations thereof; and (b) The one or more donor atoms are selected from carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), arsenic (As), and selenium (Se).

2. The compound according to claim 1, which has the following chemical structure: Wherein: (a) M is a metal center selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), and Cu(III); (b) L1, L2, L3, and L4 represent said one or more coordinating ligands, where each ligand can provide at least one donor atom for coordination with said metal center; (c) n+ / - is the charged state of said compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (d) X is a counterion for rendering said compound charge-neutral, where when X m- / + is an anion, denoted as X m- when, X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and its derivatives, where when X m- / + is a cation, denoted as X m+ when, X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cations and their derivatives; (e) m- / + is the charged state of said counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m1n; (f) represents the stoichiometry of the counterion in Formula I; and (g) the four dashed lines represent an optional independent covalent connection between two ligands, an optional independent fusion of ring portions from two ligands, or a combination thereof.

3. The compound according to claim 2, wherein L1, L2, L3 and L4 are independently selected from C6-C 50 arenes or C3-C 50 heteroarenes, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halides, alkylamines, arylamines, alkylphosphines, arylphosphines, alkylarsines, arylarsines, SCN where S is the donor atom - O-NO2 where O is the donor atom - N3 - O2 - S2 - H2O, O-NO where O is the donor atom - NCS where N is the donor atom - NH3, NO2 where N is the donor atom - N≡C - CO where C is the donor atom, R-C≡C - RO - RS - RSe - N=N=N-R, N≡C-R where N is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 PR 1 R 2 R 3 and AsR 1 R 2 R 3 where R, R 1 R 2 R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 Arylthio group, C1-C 30 Alkylthio group, C2-C 30 Carbonyl group, C1-C 30 Carboxyl group, amino group, amide group or polyaryl group (containing fused or unfused ring moieties).

4. The compound according to claim 2, wherein the dashed line represents an optional connection between two ligands; or an optional fusion of rings from different ligands.

5. The compound according to claim 1, which has the following chemical structure: wherein (a) M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II); and (b) L5 and L6 represent the one or more coordination ligands, wherein each ligand can provide at least one donor atom for coordination with the metal center; (c) L5 and L6 are independently selected from C6-C 50 aromatic hydrocarbons or C3-C 50 heteroaromatic hydrocarbons, such as five-membered aromatic hydrocarbons and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered aromatic hydrocarbons and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halides, alkylamines, arylamines, alkylphosphines, arylphosphines, alkylarsines, arylarsines, SCN where S is the donor atom - 、O-NO2 where O is the donor atom - 、N3 - 、O2 - 、S2 - 、H2O, O-NO where O is the donor atom - 、NCS where N is the donor atom - 、NH3, NO2 where N is the donor atom - 、N≡C - 、CO where C is the donor atom, R-C≡C - 、RO - 、RS - 、RSe - 、N=N=N-R, N≡C-R where N is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 、PR 1 R 2 R 3 and AsR 1 R 2 R 3 ,where R, R 1 、R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 arylthio, C1-C 30 alkylthio, C2-C 30 carbonyl, C1-C 30 carboxyl, amino, amido or polyaryl (containing fused or unfused ring moieties); (d) n+ / - is the charged state of the compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (e) X is a counterion for rendering the compound charge-neutral, wherein when X m- / + is an anion, denoted as X m- , X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and derivatives thereof, wherein when X m- / + is a cation, denoted as X m+ , X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cations and derivatives thereof; (f) m- / + is the charged state of the counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m1n; and (f) Represents the stoichiometry of the counterions described in Formula II.

6. The compound according to claim 1, which has the following chemical structure: wherein: (a) The compound exhibits a trigonal planar geometry, and M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II); (b) L7, L8, and L9 represent said one or more coordination ligands, which are independently selected from C6-C 50 arenes or C3-C 50 heteroarenes, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN where S is the donor atom - O-NO2 where O is the donor atom - N3 - O2 - S2 - H2O, O-NO where O is the donor atom - NCS where N is the donor atom - NH3, NO2 where N is the donor atom - N≡C - CO where C is the donor atom, R-C≡C - RO - RS - RSe - N=N=N-R, N≡C-R where N is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 PR 1 R 2 R 3 and AsR 1 R 2 R 3 where R, R 1 R 2 R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 Arylthio group, C1-C 30 Alkylthio group, C2-C 30 Carbonyl group, C1-C 30 Carboxyl group, amino group, amide group or polyaryl group (containing fused or unfused ring moieties); (c) Each ligand can provide at least one donor atom for coordination with the metal center; (d) n+ / - is the charged state of the compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (e) X is a counterion for rendering the compound charge-neutral, where when X m- / + is an anion, denoted as X m- , X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and derivatives thereof, where when X m- / + is a cation, denoted as X m+ , X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cations and derivatives thereof; (f) m- / + is the charged state of the counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m1n; and (f) Represents the stoichiometry of the counterion as described in Formula III.

7. The compound according to claim 1, wherein at least one of the one or more coordination ligands has the following chemical structure: wherein: (a) L represents a chemical moiety containing one or more donor atoms, preferably one donor atom, for coordinating with the metal center of the metal complex; preferably, the chemical moiety is selected from (i) five-membered aromatic hydrocarbons and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; six-membered aromatic hydrocarbons and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene; and / or (ii) halide ions, SCN where S is the donor atom - , O-NO2 where O is the donor atom - , N3 - , O2 - , S2 - , H2O, O-NO where O is the donor atom - , NCS where N is the donor atom - , NH3, NO2 where N is the donor atom - , N≡C - , C≡N - , CO where C is the donor atom, R-C≡C - , RO - , RS - , RSe - , N=N=N-R where N is the donor atom, N≡C-R where C is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 , PR 1 R 2 R 3 and AsR 1 R 2 R 3 ; where R, R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 Arylthio group, C1-C 30 Alkylthio group, C2-C 30 Carbonyl group, C1-C 30 Carboxyl group, amino group, amide group or polyaryl group (containing fused or unfused ring moieties); (b) The linking group represents a structure that facilitates an optional linking moiety between L and P / AA, where the linking group is preferably selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives and combinations thereof; (c) AA is selected from amino acids, their derivatives, or combinations of amino acids and / or their derivatives, preferably AA is selected from: (d) P represents a structure containing a positive charge, preferably substituted and unsubstituted amines, ammonium, pyridinium cations, pyrrodinium cations, phosphonium, imidazolium cations, sulfonium, and their derivatives.

8. The compound according to claim 1, having the following chemical structure: Wherein: (a) M is a metal center selected from Pt(II), Pd(II), Ni(II), Ir(I), Rh(I), Au(III), Ag(III), and Cu(III); (b) L1, L2, L3, and L4 represent the one or more coordinating ligands, where each ligand can provide at least one donor atom for coordination with the metal center; (c) n+ / - is the charged state of the compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (d) X is a counterion for neutralizing the charge of the compound, wherein when X m- / + is an anion, represented by X m- When X m- Preferably selected from chloride ions (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and its derivatives, where X m- / + is a cation, represented by X m+ When X m+ Preferably selected from K + 、Na + , Ca 2+ Mg 2+ 、Bis(triphenylphosphine)imide ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ), quaternary ammonium cations and their derivatives; (e) m- / + is the charged state of the counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m1n; (f) The stoichiometry of the counterion as described in formula V; (g) The four dashed lines represent an optional independent covalent connection between two ligands, an optional independent fusion of ring moieties from two ligands, or a combination thereof; (h) L1, L2, L3, and L4 are independently selected from C6-C 50 arenes or C3-C 50 heteroarenes, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN where S is the donor atom - 、O-NO2 where O is the donor atom - 、N3 - 、O2 - 、S2 - 、H2O, O-NO where O is the donor atom - 、NCS where N is the donor atom - 、NH3, NO2 where N is the donor atom - 、N≡C - 、CO where C is the donor atom, R-C≡C - 、RO - 、RS - 、RSe - 、N=N=N-R, N≡C-R where N is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 、PR 1 R 2 R 3 and AsR 1 R 2 R 3 ,where R, R 1 、R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 alkoxy, C3-C 30 aryloxy, C3-C 30 Arylthio group, C1-C 30 Alkylthio group, C2-C 30 Carbonyl group, C1-C 30 Carboxyl group, amino group, amide group or polyaryl group (containing fused or unfused ring moieties); (i) a, b, c, d are independently 0 or positive integers, such as 1, and a + b + c + d > 0; (j) The linking group represents a structure that facilitates an optional linking moiety between L and P / AA, where the linking group is preferably selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives and combinations thereof; (k) AA is selected from amino acids, their derivatives, or combinations of amino acids and / or their derivatives, preferably AA is selected from: (l) P represents a structure containing a positive charge, preferably a substituted and unsubstituted amine, ammonium, pyridinium cation, pyrrolidinium cation, phosphonium, imidazolium cation, sulfonium, and their derivatives.

9. The compound according to claim 1, which has the following chemical structure: Wherein: (a) M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II); (b) L5 and L6 represent said one or more coordinating ligands, where each ligand can provide at least one donor atom for coordinating with said metal center, and where L5 and L6 are independently selected from C6-C 50 arenes or C3-C 50 heteroarenes, such as five-membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six-membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3-triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4-triazine, 1,3,5-triazine, bipyridine, terpyridine, 2,6-bis(benzimidazol-2'-yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN where S is the donor atom - O-NO2 where O is the donor atom - N3 - O2 - S2 - H2O, O-NO where O is the donor atom - NCS where N is the donor atom - NH3, NO2 where N is the donor atom - N≡C - CO where C is the donor atom, R-C≡C - RO - RS - RSe - N=N=N-R, N≡C-R where N is the donor atom, C≡N-R where C is the donor atom, NR 1 R 2 R 3 PR 1 R 2 R 3 and AsR 1 R 2 R 3 where R, R 1 R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1-C 30 alkyl, C2-C 30 alkenyl, C2-C 30 alkynyl, C3-C 30 aryl, C3-C 30 heteroaryl, C1-C 30 Alkoxy, C3 - C 30 Aryloxy, C3 - C 30 Arylthio, C1 - C 30 Alkylthio, C2 - C 30 Carbonyl, C1 - C 30 Carboxyl, amino, amido or polyaryl (containing fused or unfused ring moieties); (c) e and f are independently 0 or a positive integer, such as 1, and e + f > 0; (d) The linker represents a structure that promotes an optional linking moiety between L and P / AA, wherein the linker is preferably selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives and combinations thereof; (e) AA is selected from amino acids, their derivatives, or a combination of amino acids and / or their derivatives, preferably AA is selected from: (f) P represents a structure containing a positive charge, preferably a substituted and unsubstituted amine, ammonium, pyridinium cation, pyrrolidinium cation, phosphonium, imidazolium cation, sulfonium, and their derivatives; (g) n+ / - is the charged state of the compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (h) X is a counterion for rendering the compound charge-neutral, wherein when X m- / + is an anion, denoted as X m- , X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and derivatives thereof, and when X m- / + is a cation, denoted as X m+ , X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cation and derivatives thereof; (i) m- / + is the charged state of the counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m ≠ n; and (j) Represents the stoichiometry of the counterions described in Formula VI.

10. The compound according to claim 1, which has the following structure: Wherein: (a) The compound exhibits a trigonal planar geometry, and M’ is a metal center selected from Ni(0), Pd(0), Pt(0), Cu(I), Ag(I), Au(I), Zn(II), Cd(II), and Hg(II); (b) L7, L8, L9 represent said one or more coordination ligands, where each ligand can provide at least one donor atom for coordinating with said metal center, where L7, L8, L9 are independently selected from C6 - C 50 arenes or C3 - C 50 heteroarenes, such as five - membered arenes and their derivatives, including but not limited to furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, benzofuran, isobenzofuran, indole, isoindole, benzothiophene, benzo[c]thiophene, benzimidazole, purine, indazole, benzisoxazole, benzothiazole; and / or six - membered arenes and their derivatives, including but not limited to benzene, pyridine, pyrazine, pyrimidine, pyridazine, 1,2,3 - triazine, naphthalene, anthracene, quinoline, isoquinoline, quinoxaline, acridine, quinazoline, cinnoline, phthalazine, 1,2,4 - triazine, 1,3,5 - triazine, bipyridine, terpyridine, 2,6 - bis(benzimidazol - 2′ - yl)pyridine, carbazole, dibenzothiophene, dibenzofuran, fluorene, halide, alkylamine, arylamine, alkylphosphine, arylphosphine, alkylarsine, arylarsine, SCN where S is the donor atom - 、O - NO2 where O is the donor atom - 、N3 - 、O2 - 、S2 - 、H2O, O - NO where O is the donor atom - 、NCS where N is the donor atom - 、NH3, NO2 where N is the donor atom - 、N≡C - 、CO where C is the donor atom, R - C≡C - 、RO - 、RS - 、RSe - 、N=N=N - R, N≡C - R where N is the donor atom, C≡N - R where C is the donor atom, NR 1 R 2 R 3 、PR 1 R 2 R 3 and AsR 1 R 2 R 3 ,where R, R 1 、R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C1 - C 30 alkyl, C2 - C 30 alkenyl, C2 - C 30 alkynyl, C3 - C 30 aryl, C3 - C 30 heteroaryl, C1 - C 30 Alkoxy, C3-C 30 Aryloxy, C3-C 30 Arylthio, C1-C 30 Alkylthio, C2-C 30 Carbonyl, C1-C 30 Carboxyl, amino, amide or polyaryl (containing fused or unfused ring moieties); (c) g, h, and i are independently 0 or a positive integer, such as 1, and g + h + i > 0; (d) The linker represents a structure that promotes an optional linking moiety between L and P / AA, wherein the linker is preferably selected from unsubstituted and substituted alkyl, unsubstituted and substituted heteroalkyl, unsubstituted and substituted alkenyl, unsubstituted and substituted heteroalkenyl, unsubstituted and substituted alkynyl, unsubstituted and substituted heteroalkynyl, unsubstituted and substituted aryl, unsubstituted and substituted heteroaryl, unsubstituted and substituted sulfonyl, unsubstituted and substituted amide groups, unsubstituted and substituted azo groups, unsubstituted and substituted acyl groups, unsubstituted and substituted ester groups, unsubstituted and substituted carbonate groups, unsubstituted and substituted ether groups, unsubstituted and substituted aminooxy, unsubstituted and substituted hydroxyamino, and their derivatives and combinations thereof; (e) AA is selected from amino acids, their derivatives, or combinations of amino acids and / or their derivatives, preferably AA is selected from: (f) P represents a structure containing a positive charge, preferably a substituted and unsubstituted amine, ammonium, pyridinium cation, pyrrolidinium cation, phosphonium, imidazolium cation, sulfonium, and their derivatives; (g) n+ / - is the charged state of the compound, where n is zero or a positive integer, such as 1, 2, 3, 4, and 5; (h) X is a counterion for rendering the compound charge-neutral, wherein when X m- / + is an anion, denoted as X m- , X m- is preferably selected from chloride ion (Cl - ), hexafluorophosphate (PF6 - ), nitrate (NO3 - ), perchlorate (ClO4 - ), tetrafluoroborate (BF4 - ), tetraphenylborate (B(C6H5)4 - ), trifluoromethanesulfonate (CF3SO3 - ), dihydrogen phosphate (H2PO4 2- ), sulfate (SO4 2- ), hydrogen phosphate (HPO4 2- ), phosphate (PO4 3- ) and derivatives thereof, wherein when X m- / + is a cation, denoted as X m+ , X m+ is preferably selected from K + , Na + , Ca 2+ , Mg 2+ , bis(triphenylphosphine)iminium ion ([(C6H5)3P)2N] + ), phosphonium, pyridinium cation ([C5H5NH] + ) and quaternary ammonium cations and derivatives thereof; (i) m- / + is the charged state of the counterion, where m is zero or a positive integer, such as 1, 2, 3, 4, and 5, where m = n or m ≠ n; and (j) Represents the stoichiometry of the counterion described in Formula VII.

11. The compound according to claim 1, which is capable of binding to an analyte through non-covalent interactions such as electrostatic interactions, hydrogen bond interactions, hydrophobic interactions, and combinations thereof.

12. The compound according to claim 1, wherein the compound exhibits a square planar, trigonal planar, partially planar, or linear geometric configuration.

13. The compound according to claim 11, wherein the analyte is capable of inducing self-assembly of the compound, preferably wherein the self-assembly results in changes in the photophysical properties of the compound, such as changes in ultraviolet-visible light absorbance, emission wavelength, emission intensity, emission lifetime, circular dichroism, circularly polarized luminescence, or combinations thereof, preferably wherein the changes are used to sense the analyte.

14. The compound according to claim 1, which has the following structure: where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III), or Cu(III); wherein M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III); Where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III), n represents the charge number of the metal complex in the formula, where n is zero or a positive integer, X represents the counterion for neutralizing the charge, where n is zero or a positive integer, m = n or m1n, represents the stoichiometry of the counterion in the formula; Where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III), n represents the charge number of the metal complex in the formula, where n is zero or a positive integer, X represents the counterion for charge neutrality, where n is zero or a positive integer, m = n or m1n, represents the stoichiometry of the counterion in the formula; Where M represents the metal center, preferably selected from Ir(I), Rh(I), Pt(II), Pd(II), Ni(II), Au(III), Ag(III) or Cu(III), n represents the charge number of the metal complex in the formula, where n is zero or a positive integer, X represents the counterion for charge neutrality, where n is zero or a positive integer, m = n or m1n, represents the stoichiometry of the counterion in the formula.

15. The compound according to claim 11, wherein the analyte is a glycan such as sialic acid or polysialic acid; and / or cancer cells.

16. A method for sensing or imaging an analyte in a sample (preferably a biological sample), the method comprising: (a) Combine the compound according to claim 1, preferably in a container, and optionally subsequently mix the compound with the sample; and (b) Measure the change in the photophysical properties of the compound, and optionally check whether supramolecular self-assembly of the compound occurs, and preferably induce the supramolecular self-assembly by combining the compound with the sample.

17. The method according to claim 16, wherein the change in the photophysical properties of the compound indicates a change in the supramolecular self-assembly and aggregation behavior of the compound, and wherein the change indicates the presence of an analyte.

18. The method according to claim 16, wherein the analyte that can be sensed or imaged includes glycans such as sialic acid or polysialic acid; and / or cancer cells.

19. The method according to claim 16, wherein the sample includes body fluids (such as blood, plasma, serum), cells (such as eukaryotic cells, which are optionally selected from 3T3 cells, HeLa cells, HepG2 cells, MCF7 cells, HEK293T cells, Chinese hamster ovary (CHO) cells and other cells), tissues (such as brain tissue, heart tissue, liver tissue, kidney tissue, spleen tissue, lung tissue, etc.) or animals.

20. A method for testing the efficacy of an inhibitor in removing an analyte or inhibiting the generation of an analyte, the method comprising: (1) Mix the compound according to claim 1 with a sample treated with an inhibitor and a corresponding sample not treated with the inhibitor; (2) Measure the change in the photophysical properties of the compound to study the change in the degree of supramolecular self-assembly of the complex, preferably wherein the change in the photophysical properties indicates a change in the self-assembly and aggregation behavior of the compound.

21. A kit comprising the compound according to claim 1 in one or more containers and optionally positive controls, negative controls and / or instructions for using the kit.

22. The kit according to claim 21, wherein the compound is capable of detecting and / or imaging an analyte, wherein the analyte is selected from glycans such as sialic acid or polysialic acid; and / or cancer cells.

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