Antimonene-gold nano composite material as well as preparation method and application thereof

Abstract

The multifunctional antimonene-gold nano composite material (AM-Au NCs) is rapidly, simply and conveniently prepared and is used for multi-analyte fluorescence sensing (such as metal ions, CD63 and tumor-derived exosomes), molecular information coding and protection. Sodium dodecyl benzene sulfonate, AM, Au < 3 + > and NaBH4 are mixed by using different formulas at room temperature to prepare AM-Au NCs with an adjustable gold nanostructure and characteristics. And interestingness is that AM-Au NCs doped with the gold nanoparticles show wide fluorescence quenching capability on the nanosheets, and the fluorescence quenching capability is remarkably different in different dyes and DNA (deoxyribonucleic acid) consisting of different basic groups. A fluorescent sensing platform constructed by AM-Au NCs is combined with a dye or an aptamer and is used for detecting metal ions, CD63 and tumor-derived exosomes. In real samples, through binary or digital coding of selective response and diversified DNA sequences of sensing systems, a series of molecular encryption and hiding technologies are provided and applied to realize molecular-level protection of special text information.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite materials, in particular to a Sb-ene-gold nanocomposite material and a preparation method and application thereof. BACKGROUND

[0002] Life as a complex multiscale system operates, covering dimensions from nanometers to microns and larger scales, characterized by complex molecular interactions and sophisticated information processing and communication networks. In-depth understanding of these natural systems and simulating their emergent functions have become the primary goal of researchers in various scientific fields. Among the many promising approaches, the bottom-up strategy of building molecular or nanoscale systems using molecular building blocks has achieved remarkable examples of simulation applications. For example, researchers have designed and developed a variety of DNA-based systems, including aptamer sensing (such as detection of tumor-derived exosomes (TDEs) or their markers CD63, epithelial cell adhesion molecule (EpCAM), etc.), DNA machines, DNA origami structures, DNA logic devices, DNA storage systems, DNA cryptography and / or steganography, using the molecular recognition and self-assembly properties of DNA. These innovations have found applications in multiple fields such as sensing, medicine, catalysis and information technology. At the same time, with the continuous evolution of DNA properties, a flexible and scalable family of two-dimensional (2D) materials (especially graphene and its derivatives, MXenes, transition metal dichalcogenides) has also begun to make its presence felt in complex molecular networks (DNA reaction networks) and multifunctional applications (disease diagnosis, drug delivery, neural network computing). For example, Ti3C2 MXenes nanosheets adsorbed Cy3-labeled CD63 aptamers and quenched their fluorescence, and TDEs-labeled CD63 can be detected by fluorescence resonance energy transfer (FRET). After CD63 aptamer adsorption by graphitic carbon nitride (g-C3N4) nanosheets, the catalytic activity of tetramethylbenzidine was improved, which can be used for sensitive colorimetric detection of TDEs in breast cancer cell lines. A peptide-graphene sensing system was comprehensively used for dual-signal (fluorescence and resonance light scattering (RLS)) sensing of TDEs, logic computation and information protection. In order to enhance the performance of artificial molecular or nanoscale systems, scientists are constantly trying to switch multiple components, abstract internal signal patterns, and digitize these intrinsic relationships. However, as a solid foundation for preparation, the improvement of the material platform is still an indispensable key aspect. The current challenges facing this field include cumbersome preparation processes, poor functionality and limited paradigms.

[0003] Antimonene (AM) is a newly emerging two-dimensional material that exhibits good properties, including a large surface area and the ability to interact with a variety of biomolecules, such as DNA and peptides. These properties make AM a promising candidate material for a wide range of applications, including biosensing, energy, and biomedical applications. For example, due to its strong interaction with single-stranded nucleic acids (ssDNA or ssRNA), antimonene can bind to these nucleic acids, creating a sensing system for the electrochemical and surface plasmon resonance detection of micro RNAs and DNA. In addition, the application of peptide-based sensing, logic computing, and information security on the antimonene platform has also been demonstrated. The introduction of metal nanoparticles (NPs) to the surface of two-dimensional materials has been shown to significantly enhance their performance and functional properties, including improvements in optical properties, electrical conductivity, and catalytic activity. This strategy has been effectively implemented in a variety of applications, including chemical / biological sensing, biomedical, and energy conversion. Although AM-metal nanoparticle composites, particularly those with intercalated metal NPs, have potential, their synthesis and multifunctional applications in sensing and information technology have not been extensively explored. SUMMARY

[0004] In order to solve the problems of the prior art, the present application discloses an antimonene-gold nanoparticle composite material, a preparation method thereof and applications thereof.

[0005] The technical scheme of the present application specifically includes:

[0006] The present application provides a preparation method of an antimonene-gold nanoparticle composite material, using NaBH4 as a reducing agent and SDBS as a protective agent, AM and Au 3+ are mixed at room temperature.

[0007] The combination of the above four substances is evaluated for the formation of the product by color, Dillar effect photography and absorption spectrum measurement. Specifically, when all four components are combined, a stable purple solution is observed (due to the Au 3+ colloids a, b, and c exhibit pink purple, deep purple red, and deep purple, respectively, and the yellow colloids obtained when the characteristic absorption peak is at 500-600 nm are the surface-prepared antimonene-gold nanoparticle composite material.

[0008] The specific preparation process includes: by mixing 300 μL of ultrapure water, 300 μL of SDBS with a concentration of 20 mM, 100 μL of AM with a concentration of 30 mg / mL, and 100 μL of KAuCl4 with a concentration of 10 mM at room temperature; after adding 200 μL of NaBH4 with a concentration of 10 mM and stirring for 5 seconds, the solution turns blue-purple; the final yellow colloids are the antimonene-gold nanoparticle composite material, with a concentration of 3 mg / mL.

[0009] The present invention further provides an antimonene-gold nanocomposite material, the structure of which consists of AM nanosheets and Au nanoparticles embedded on the surface of the AM nanosheets.

[0010] The diameter and density of the Au nanoparticles can be adjusted by changing the concentration ratio of Au3+ and NaBH4.

[0011] This invention also provides an application of antimonene-gold nanocomposite material in the preparation of fluorescence quenchers; fluorescence quenching is achieved through energy transfer between fluorescent dyes and AM-Au NCs.

[0012] This invention also discloses the application of quenchers containing antimonene-gold nanocomposites in the detection of metal ions.

[0013] This invention also discloses the application of antimony-gold nanocomposite materials in the detection of CD63 and tumor exosomes.

[0014] Application of antimonene-gold nanocomposites in information encryption.

[0015] This invention provides a rapid and simple method for preparing multifunctional antimonyene-gold nanocomposites (AM-Au NCs) and for their application in multianalyte fluorescence sensing (e.g., metal ions, CD63, and tumor-derived exosomes), molecular information encoding, and protection. Sodium dodecylbenzenesulfonate (SDBS), AM, and Au are incorporated using different formulations at room temperature. 3+ By mixing with NaBH4, AM-Au NCs with tunable gold nanostructures and properties were prepared. Interestingly, AM-Au NCs doped with gold nanoparticles (Au NPs) exhibited broad fluorescence quenching capabilities on nanosheets, which varied significantly across different dyes and DNAs with different base compositions. A fluorescence sensing platform constructed using AM-Au NCs, combined with dyes or aptamers, was used to detect metal ions, CD63, and tumor-derived exosomes. The unique selection of this fluorescence system... Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the preparation and related applications of antimonyene-gold nanocomposites (AM-Au NCs) according to this invention. Part A shows the preparation of the multifunctional AM-Au NCs of this invention; Part B shows the invention's broad fluorescence quenching capability; Part C shows the invention's application in multi-analyte fluorescence sensing; and Part D shows the comprehensive application in molecular information protection.

[0017] Figure 2A These are photographs showing the colors and Tyndall effect of different reaction solutions prepared with AM-Au NC. The solutions contain AM, SDBS, and Au. 3+The final concentrations of AM, SDBS, Au

[0018] Figure 2B is the superimposed plot of the absorption spectra of the experimental and control groups of AM-Au NCs, the above-mentioned solutions of AM, SDBS, Au 3+ The final concentrations of AM, SDBS, Au

[0019] Figure 2C are the color and Tyndall effect photos of the colloidal solution after the four substances mixed for 30 minutes at three concentration ratios;

[0020] Figure 2D are the absorption spectra of the colloidal solution after the four substances mixed for 30 minutes at three concentration ratios;

[0021] Figure 2E are the low and high magnification transmission electron microscopy (TEM) images of the three colloidal solutions in panel C. E corresponds to a in panel C. Scale bars, 200 and 20 nanometers. (E3) The statistical histogram of the diameters of AM surface nanoparticles in the a colloidal solution obtained by measuring the TEM images using lmageJ software. The red line is the Gaussian fitting of the data.; (E5-E12) HAADF-TEM images (E5) and EDS element mapping (E6-E12) of AM-Au NCs. Scale bars, 100 nanometers.

[0022] Figure 2F are the low and high magnification transmission electron microscopy (TEM) images of the three colloidal solutions in panel C. F corresponds to b in panel C. Scale bars, 200 and 20 nanometers.; (F3) The statistical histogram of the diameters of AM surface nanoparticles in the b colloidal solution obtained by measuring the TEM images using lmageJ software. The red line is the Gaussian fitting of the data.

[0023] Figure 2G are the low and high magnification transmission electron microscopy (TEM) images of the three colloidal solutions in panel C. G corresponds to c in panel C. Scale bars, 200 and 20 nanometers.; (G3) The statistical histogram of the diameters of AM surface nanoparticles in the c colloidal solution obtained by measuring the TEM images using lmageJ software. The red line is the Gaussian fitting of the data.

[0024] Figure 2H is a schematic diagram of the synthesis principle of AM-Au NCs.

[0025] Figure 3(A) XRD of AM-Au NCs. (B and C) FTIR spectra of AM-Au NCs (B) and AM (C). (D-H) XPS full spectra (D) and Au 4f (E), Sb 3d (F), C 1s (G), and S 2p (H) core level spectra of AM-Au NCs and AM. (I) ζ-potential of AM-Au NCs.

[0026] Figure 4 (A1-A3) AM-Au NCs caused changes in the fluorescence emission spectra of three common fluorescent dyes including fluorescein: 0.5 μΜ, rhodamine B: 1.25 μΜ, and AO: 2 μΜ. Inset: fluorescence photos of three fluorescent dyes solutions before and after the addition of AM-Au NCs. (B1-B4) AM-Au NCs changed the fluorescence emission spectra of single-stranded DNA with different base sequences including A33, T33, C33, G33, all at 100 nM. (C) Comparison of the fluorescence quenching rates of AM-Au NCs on fluorescent dyes at different concentrations (3 mg / mL: 1 mM, 0-32 μL). (D) Comparison of the fluorescence quenching rates of AM-Au NCs on single-stranded DNA and fluorescein sodium at different concentrations (3 mg / mL: 1 mM, 0-32 μL or 0-80 μL).

[0027] Figure 5 is (A, B) fluorescence emission spectra (A) and changes in fluorescence intensity at 530 nm (F0-F) / F0 (B) of AO-AM-Au complex obtained after the addition of 18 metal ions (5 μΜ) (398 μL of AO (2 μΜ) mixed with 2 μL of AM-Au NCs (3 mg / mL: 1 mM)). (C) Schematic diagram of the interaction between AO, AM-Au NCs and Al 3+ (D) Fluorescence emission spectra of AO-AM-Au complex after the addition of different concentrations of Al3+(0-100 μΜ). (E) Dependence of changes in fluorescence intensity at 530 nm (F0-F) / F0 of AO-AM-Au NCs on Al 3+ concentration. (F) Linear relationship between (F0-F) / F0 and Al 3+ concentration in the range of 0 to 10 μΜ and 20 to 100 μΜ. Buffer: 5 mM Tris-HAc, pH 7.0.

[0028] Figure 6 is the fluorescence emission spectra changes under different combinations of molecular events. (A) is CD63 aptamer, 100 nM; AM-AuNCs, 3 mg / mL: 1 mM; CD63, 192 nM; buffer: Tris-HAc (5 mM, pH = 7.4). (B) is a schematic diagram of the interaction between CD63 aptamer, AM-AuNCs and CD63. (C) is the fluorescence selective response of CD63 aptamer-AM-Au nanoprobe (100 nM: 3 mg / mL: 1 mM) to CD63 and common interferents (CD133, BSA, lysozyme, all at a concentration of 192 nM). (D) is the fluorescence emission spectra of CD63 aptamer-AM-Au nanoprobe (100 nM: 3 mg / mL: 1 mM) after the addition of different concentrations of CD63 (0.2-480 nM).

[0029] Figures 7A to 7F is a nanoparticle tracking analysis graph of TDEs. Wherein: (A) is a transmission electron microscope (TEM) image of TDEs. Scale bar: 200 and 100 nanometers. (B) is the fluorescence emission spectra of CD63 aptamer-AM-Au nanoprobe (100 nM: 3 mg / mL: 1 mM) after the addition of different concentrations of TDEs. (C) is the relationship between the fluorescence response (F-F0) / F0 of CD63 aptamer-AM-Au at 520 nanometers and the concentration of TDEs.

[0030] Figure 8is the molecular cryptography and steganography utilizing AM-Au NCs. (A) The basic hybrid model containing reversible encryption-decryption (a1) and steganalysis (a2) processes. (B) Selective response of AO-AM-Au NCs to 18 metal ions for molecular cryptography-steganography. (B1) AO-AM-Au NCs as steganographic objects, receiving 18 metal ions as steganographic keys to generate fluorescent outputs. (B2) The steganalysis process decodes the selective response to obtain the hidden information (i.e., 18-bit binary string), which is performed according to an arbitrary threshold. (B3) The basic rules of splitting the binary string and encoding information. (B4) Three examples (e.g., 1-3) are given and combined to show the process of decrypting and obtaining the corresponding secret messages using the correct keys. (C) The aptamer-AM-Au-based molecular cryptography-steganographic sensing system. (C1) Using CD63 aptamer as information carrier and AM-Au NCs as nanocover to form aptamer-AM-Au as steganographic objects (a), CD63 or TDEs as molecular steganographic keys (b) to unlock the aptamer-AM-Au steganographic objects (c) and obtain the protected information based on the aptamer sequence (d). (C2) The structure of information encoding in DNA strands for encrypting and hiding information. (C3) The corresponding decoding rules, diagrams, 7-bit (a) or 6-bit (b) keys, and the secret texts hidden and encrypted in DNA. These pictures respectively imply the meaning or source of the secret message. DETAILED DESCRIPTION

[0031] The application will be described in detail below with reference to examples.

[0032] 2. Experimental Section

[0033] 2.1. Materials and reagents. Antimony powder was purchased from Alfa Aesar (China). Sodium borohydride (NaBH4) was provided by National Pharmaceutical Group Chemical Reagent Co., Ltd. (Shanghai, China). Sodium dodecyl benzene sulfonate (SDBS), potassium chloroaurate (KAuCl4), potassium nitrate (KNO3), sodium nitrate (NaNO3), ferric nitrate (Fe(NO3)3·9H2O), calcium nitrate (Ca(NO3)2), lead nitrate (Pb(NO3)2), mercury nitrate (Hg(NO3)2), cadmium nitrate (Cd(NO3)2), aluminum nitrate (Al(NO3)3), magnesium nitrate (Mg(NO3)2), copper nitrate (Cu(NO3)2), zinc nitrate hexahydrate (Zn(NO3)2·6H2O), manganese nitrate (Mn(NO3)2), cobalt nitrate hexahydrate (Co(NO3)2·6H2O), nickel nitrate (Ni(NO3)2), barium nitrate (Ba(NO3)2), beryllium sulfate tetrahydrate (BeSO4·4H2O), chromium nitrate (Cr(NO3)3), and bismuth nitrate (Bi(NO3)3) were purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). All aqueous solutions were prepared using ultrapure water produced by a Milli-Q system (Millipore, Bedford, MA, USA, 18.2 MΩ·cm).

[0034] Recombinant human CD63 protein fragment (Ala 103-Val 203, purity >95%, Cat. No. 11271-H08H, Uniprot No. P08962-1) was provided by Sinobiological Technology Co., Ltd. (Beijing, China). Mouse CD133 protein was purchased from Sino Biological Inc. (USA). Bovine serum albumin (BSA) and lysozyme were purchased from Sigma. Thirty-three consecutive adenine sequences (A33), thirty-three consecutive thymine sequences (T33), thirty-three consecutive cytosine sequences (C33), twenty-nine guanine and four thymine inserted as a spacer (G33, Note: Due to the limitations of artificial synthesis technology, it is difficult to synthesize complete G DNA, so some T bases are introduced in G33), and CD63 binding aptamer (its sequence and modification are shown in Table 1) were synthesized by Shanghai Sanggen Biotechnology Co., Ltd.

[0035] Table 1. Sequence and modification of CD63 aptamer for CD63 protein

[0036]

[0037] 2.2. Preparation and characterization of AM-Au NCs. AM was prepared using a modified previous method. Specifically, 0.3 g of antimony powder was dispersed in 10 mL of absolute ethanol and treated with 3 seconds on / off sonication pulses using a JY92-II ultrasonic cell disrupter (Ningbo Xinzhi Biological Technology Co., Ltd., China) at 100% amplitude and 800 W power for 3 hours in an ice bath. The mixture was then centrifuged at 1500 relative centrifugal force (RCF) for 10 minutes in a 5424R centrifuge (Eppendorf, Germany) to obtain a solution of AM nanosheets. The concentration of the obtained AM nanosheets was 30 mg / mL.

[0038] The synthesis of AM-Au NCs was performed by mixing 300 pL of ultrapure water, 300 pL of 20 mM SDBS, 100 pL of 30 mg / mL AM, and 100 pL of 10 mM KAuCl4 at room temperature. After the addition of 200 pL of 10 mM NaBH4 and stirring for 5 seconds, the solution turned blue-violet. The final concentration of the yellow colloid (AM-Au NCs) was 3 mg / mL 1 mM, based on the amount of AM and Au used. 3+

[0039] Absorption and fluorescence spectra were recorded using a SpectraMax M5 microplate spectrophotometer (Molecular Devices, USA). The purified AM-Au NCs samples were deposited on clean silicon chips or copper grids and naturally air-dried before imaging using a Tecnai G2 F20 transmission electron microscope (TEM, FEI, USA) equipped with an energy dispersive spectrometer (EDS). Particle size distribution was analyzed using Image J software and Gaussian fitting. In addition, the crystal phase, surface functional groups, and elemental composition of the AM-Au NCs were characterized using an X-ray diffraction (XRD) system (Bruker D8, Germany), an IS10 Fourier transform infrared (FTIR) spectrometer (Nicolet, USA), and an ESCALAB 250xi X-ray photoelectron spectrometer (XPS, Thermo Scientific, USA), respectively. Zeta potential was measured by a Zetasizer Nano ZS90 nanopotential system (Malvern, UK).

[0040] ​2.3. Fluorescence quenching ability of AM-Au NCs. Three common fluorescent dyes and four FAM-labeled single-stranded DNAs (T33, A33, C33, and G33) were chosen to evaluate the fluorescence quenching ability of AM-Au NCs. 400 μL of sodium fluorescein (0.5 μM), rhodamine B (1.25 μM), acridine orange (2 μM), FAM-labeled single-stranded DNAs (T33, A33, C33, and G33; 100 nM) solutions were added into a microfluorometer cuvette with a 2-mm slit, and the fluorescence emission spectra of these solutions were recorded at different excitation wavelengths (475, 550, 490, 485 nm) with the ranges of 500-700 nm, 565-700 nm, 510-700 nm, and 495-700 nm, respectively. Subsequently, different concentrations of AM-Au NCs were added into these solutions, and the fluorescence emission spectra of the mixtures were measured under the corresponding conditions. By processing the obtained spectral data, the fluorescence quenching rates of AM-Au NCs on various dyes were evaluated as (F0-F) / F0.

[0041] 2.4. Cell culture, extraction, and characterization of TDEs. The human cervical squamous cell carcinoma SiHa cell line was obtained from the National Accredited Cell Bank (Shanghai, China). Cells were cultured in DMEM medium (Hyclone, USA) supplemented with 10% fetal bovine serum (Gibco, USA), 100 U / mL penicillin, and 100 μg / mL streptomycin, and incubated at 37 °C in a humidified atmosphere of 5% CO2. When SiHa cells reached 80-90% confluence, the medium was replaced with DMEM containing 10% exosome-depleted serum (C3801-0050, VivaCell), and incubated for 48 h. The supernatant was collected and placed on ice for exosome isolation using an exosome concentration kit (ThermoFisher Scientific, USA). The isolation process included the following steps:

[0042] (1) Sample pre-treatment: Cell culture supernatant was centrifuged at 3,000 x g for 10 min at 4°C to remove cells and impurities. The supernatant was transferred to a new tube for later use. (2) Exosome binding and enrichment: 5 mL of treated supernatant was mixed repeatedly with 0.5 mL of binding buffer in a 15 mL centrifuge tube. 200 μL of binding resin was added, mixed for 15 min at room temperature, and then centrifuged at 1,500 x g for 2 min. The excess supernatant was removed, 400 μL was retained, the resin was resuspended and transferred to a purification column, and centrifuged at 2,000 x g for 2 min. The filtrate was discarded, and the purification column was returned to the collection tube. (3) Exosome washing: 500 μL of washing solution was added to the collection tube containing the purification column. After 3 min of standing, it was centrifuged at 3,000 x g for 2 min, and the filtrate was discarded. (4) Exosome elution: The purification column was transferred to a 1.5 mL low-adsorption centrifuge tube. After 200 μL of elution solution was added, it was allowed to stand for 5 min, and then centrifuged at 300 x g for 2 min. The filtrate was re-added, allowed to stand for 2 min, and then centrifuged at 3,000 x g for 2 min. The resulting liquid was a concentrated exosome solution, which was resuspended in 1 x PBS and stored at -80°C for later use.

[0043] For transmission electron microscopy (TEM) analysis, 10 μL of TDEs solution (1.75 x 10^5 particles / mL) was placed on a copper grid and allowed to stand for 10 min. Subsequently, 10 μL of 2.5% uranyl acetate was added, and the grid was allowed to stand for 1 min before the excess stain was removed and air-dried. Imaging was performed using a transmission electron microscope (JEM-1200EX, JEOL, Japan) at 100 kV under high vacuum. For analysis of the size and concentration of TDE particles, purified TDEs were diluted with 1 x PBS (Biological Industries, Israel) before measurement, and then measured using nanoparticle tracking analysis (NTA, ZetaView PMX 110, Particle Metrix, Meerbusch, Germany) and ZetaView software (version 8.05.14SP7), with calibration using 110 nm polystyrene particles. NTA measurements recorded and analyzed from at least 11 locations.

[0044] 2.5 Sensing detection of multiple analytes of metal ions, CD63, and CD63+exosomes based on AM-Au NCs. For detection of metal ions, AO-AM-Au nanoprobes were prepared by adding 2 μL of AM-Au NCs (3 mg / mL: 1 mM) to 400 μL of 2 μM acridine orange for 5 min. The fluorescence emission spectrum of the AO-AM-Au nanoprobes mixed with the metal ion mixture was measured before and after the addition of different concentrations of metal ions and reacted for 5 min, and the quenching rate (F0-F) / F0 was calculated.

[0045] For the detection of CD63 or CD63+exosomes, CD63 aptamer-AM-Au nanoprobes were prepared by adding 100 pL of AM-Au NCs (3 mg / mL: 1 mM) into 400 pL of 100 nM CD63 aptamer for 5 min. Then, different concentrations of CD63 or CD63+exosomes were added into the prepared CD63 aptamer-AM-Au nanoprobes. For the selectivity experiment, CD63 was replaced by CD133, BSA and lysozyme at the same concentration.

[0046] 2.6. Real sample analysis. Firstly, tap water samples were filtered by 0.22-micron filter membranes and used as solvents to dilute standard aluminum ion (Al 3+ ) solutions. Then, tap water samples with known concentrations of aluminum ion (Al 3+ ) were added into the AO-AM-Au nanoprobes solution. After 5 min of reaction at room temperature, the fluorescence intensity of the mixture was measured.

[0047] 2.7. Molecular cryptography and steganography. In the molecular cryptogram steganography based on the selective response of AO-AM-Au nanoprobes, 18 metal ions (as steganographic keys) were input into the AO-AM-Au nanoprobes (as steganographic objects) to produce fluorescence selective responses. Then, these responses were converted into 18-bit binary strings based on the appropriate threshold set. The 18-bit binary strings were segmented into 12 7-bit or 11 8-bit strings. Finally, by querying the corresponding cipher table, these binary strings were further interpreted into understandable information (decrypted secret information, please note: here, 7-bit and 8-bit each show three sets of corresponding information encoding and encryption key tables). All the above experimental operations are the same as the selectivity of AO-AM-Au nanoprobes to metal ions.

[0048] For the aptamer-AM-Au-based molecular cryptogram steganography sensing system, CD63 aptamer was used as the information carrier, AM-Au NCs as the nanoshield forming aptamer-AM-Au steganographic objects, and CD63 or TDEs as molecular steganographic keys to unlock the aptamer-AM-Au steganographic objects and obtain protected information based on the aptamer sequence. The 32-base CD63 aptamer used DNA sextuples (6 bases, 4 6 = 4096) or heptuples (7 bases, 4 7=16384) Encodes 27 or 26 characters by sequentially shifting one base from the 5′ end. The presence of target CD63 or TDEs causes fluorescence recovery, (F-F0) / F0 > 0.2, revealing its DNA sequence. By searching the corresponding code table, the characters contained in the DNA can be decrypted, and by merging and recognizing them, the corresponding intelligible short text information can be obtained (note: here, two sets of code tables corresponding to DNA hexagrams and septuplets are shown to encode and encrypt information).

[0049] 3. Results and Discussion

[0050] 3.1. Preparation and characterization of AM-Au NCs.

[0051] To synthesize AM-Au NCs, NaBH4 was used as a reducing agent and SDBS as a protecting agent, along with AM and Au. 3+ The mixture was prepared at room temperature. The formation of the product was assessed by color, Tyndall effect photography, and absorption spectroscopy measurements. A stable blue-violet solution was observed only when all four components were combined, with a characteristic absorption peak at approximately 534 nm. Figure 2A B). In contrast, AM+Au 3+ The mixture of AM and NaBH4 produced a noticeable black precipitate after 30 minutes due to the lack of SDBS. Furthermore, AM + Au... 3+ +SDBS and AM+Au 3+ The mixture, lacking a reducing agent, did not show any color change or characteristic absorption peaks, indicating that no nanocomposite material was formed. Figure 2A These findings confirm that NaBH4, SDBS, AM, and Au can be used at room temperature. 3 + Synthesize stable nanocomposite materials.

[0052] Furthermore, we selected three reaction systems (labeled colloids a, b, and c, respectively) for detailed characterization, and their products showed significant differences. Figure 2C As shown in D, due to Au 3+ With different concentration ratios of NaBH4, colloids a, b, and c exhibited pinkish-purple, deep purplish-red, and deep purple hues, respectively, corresponding to a moderately sharp peak at 514 nm, a low-broad peak at 560 nm, and a strong-broad peak at 564 nm. Their differences were further observed using transmission electron microscopy (TEM). Colloid a consisted of a large number of Au nanoparticles (average diameter 4.39 ± 0.05 nm (R0)). 2 =0.998), Figure 2E3) embedded on the surface of AM nanosheets ( Figure 2EThe composition is as follows. The high-resolution TEM image in Figure 2E4 shows that colloid a has lattice fringes with average spacing of 0.19 nm and 0.21 nm, corresponding to the (006) plane of Sb and the (111) plane of Au, respectively. The high-angle annular dark-field scanning TEM (HAADF-STEM) image and EDS elemental mapping results of colloid a show that Au nanoparticles (yellow) are uniformly distributed on the surface of AM nanosheets (orange, Figure 2E5-E8). S, C and O elements are uniformly distributed throughout the surface of AM-Au NCs, indicating that SDBS is stably adsorbed on them (Figure 2E5-E6, E10-E12). The deep purple-red colloid b has relatively few Au nanoparticles (average diameter 6.46 ± 0.13 nm (R)) dispersed on AM nanosheets. 2 =0.998), Figure 2F1-F3). The deep purple colloid c shows a large number of cross-linked Au nanoparticles attached to the AM nanosheets (although the average diameter of a single Au nanoparticle is approximately 5.99 ± 0.04 nm (R = 0.998), Figure 2F1-F3). 2 =0.993), Figure 2G1-G3). The above results indicate that by using different formulations and mixing SDBS, AM, and Au at room temperature, 3+ With NaBH4, we can prepare AM-AuNCs with tunable Au nanostructures. Figure 2H ).

[0053] Furthermore, we selected three reaction systems (labeled colloids a, b, and c, respectively) for detailed characterization, and their products showed significant differences. Figure 2C As shown in D, due to Au 3+ With different concentration ratios of NaBH4, colloids a, b, and c exhibited pinkish-purple, deep purplish-red, and deep purple hues, respectively, corresponding to a moderately sharp peak at 514 nm, a low-broad peak at 560 nm, and a strong-broad peak at 564 nm. Their differences were further observed using transmission electron microscopy (TEM). Colloid a consisted of a large number of Au nanoparticles (average diameter 4.39 ± 0.05 nm (R0)). 2 =0.998), Figure 2E3) embedded on the surface of AM nanosheets ( Figure 2E) composition. High-resolution TEM images in Figure 2E4 show that the colloids a have lattice fringes with an average spacing of 0.19 nm and 0.21 nm, corresponding to the (006) plane of Sb and the (111) plane of Au, respectively. High-angle annular dark-field scanning TEM (HAADF-STEM) images and EDS elemental mapping results of colloids a indicate that Au nanoparticles (yellow) are uniformly distributed on the surface of AM nanosheets (orange, Figure 2E5-E8). S, C, and O elements are uniformly distributed on the entire surface of AM-Au NCs, indicating that SDBS is stably adsorbed thereon (Figure 2E5-E6, E10-E12). Colloids b in deep magenta red have relatively fewer Au nanoparticles (average diameter 6.46 ± 0.13 nm (R 2 = 0.998), Figure 2F1-F3) scattered on AM nanosheets. While colloids c in deep purple show a large number of cross-linked Au nanoparticles attached to AM nanosheets (although the average diameter of individual Au nanoparticles is about 5.99 ± 0.04 nm (R 2 = 0.993), Figure 2G1-G3). The above results show that by using different formulations and mixing SDBS, AM, Au 3+ and NaBH4 at room temperature, we can prepare AM-Au NCs with tunable Au nanostructures. Figure 2H

[0055] Further XRD characterization Figure 3 A) shows that AM-Au NCs exhibit characteristic peaks at 2q = 31.9°, 40.3°, 43.5°, 45.5°, and 50.4°, corresponding to the (100), (104), (200), (006), and (202) planes of Sb, and the (111) plane of metallic Au. FTIR spectra Figure 3 B) confirm the functional groups in AM-Au NCs, with peaks at 3338.66, 1599.66, and 1398.62 cm -1 associated with the stretching and bending vibrations of hydroxyl (-OH) groups in adsorbed water. Peaks at 2919.22 and 2851.24 cm -1 are associated with C-H aromatic compounds, while peaks at 1168.40 and 1126.71 cm -1 indicate the stretching of S=O. The peak at 1008.59 cm -1 corresponds to -SO3H, and peaks at 720.76 and 572.27 cm -1 are associated with the stretching vibrations of Sb-O-Sb and Sb-O. Compared to AM alone Figure 3 C), the FTIR analysis of AM-Au NCs shows new functional groups related to SDBS (1168.40, 1126.71 cm​-1 representing S=0, 1008.59 cm -1 representing -SO3H), indicating the presence of SDBS on the surface of the synthesized AM-Au NCs. The XPS spectrum of AM-Au NCs shows characteristic peaks at 284.1, 85.2, 540.0, 531.6, and 167.5 eV corresponding to C1s, Au 4f, O 1s, Sb 3d, and S2p Figure 3 D), respectively. Compared with AM alone, the Au 4f core level spectrum Figure 3 E) of AM-Au NCs exhibits two distinct peaks: Au 4f 7 / 2 (83.5 eV) and Au 4f 5 / 2 (87.1 eV) with a spin energy separation of 3.6 eV. The Sb 3d core level spectra of AM and AM-Au NCs show two main peaks in the range of 525-545 eV, representing Sb 3d 5 / 2 and Sb 3d 2 / 3 ( Figure 3 F), respectively. Notably, the Sb 3d 5 / 2 peak of AM-Au NCs shifts from 530.5 eV to 531.8 eV compared with AM alone, indicating a decrease in the electron density around Sb due to the presence of foreign sulfur atoms in SDBS, with a change of 1.3 eV, suggesting enhanced interfacial interaction between SDBS and AM-Au NCs. The C1s core level spectrum Figure 3 G) of AM-Au NCs shows two peaks of C-C (284.7 eV) and C=C (286.1 eV), indicating the presence of SDBS. In addition, the peak of S2p at 168.1 eV suggests the presence of SDBS molecules or derivatives Figure 3 H), confirming the adsorption of SDBS on the surface of AM-Au NCs, which contributes to their stable dispersion in aqueous solution. The zeta potential indicates that the surface of AM-Au NCs is negatively charged (-30.1 mV) due to the modification of the cationic surfactant SDBS Figure 3 l). These results indicate that AM-Au NCs coated with SDBS can be successfully prepared by mixing SDBS, AM, Au3+, and NaBH4 at room temperature for 5 min.

[0057] 3.2. Fluorescence quenching ability of AM-Au NCs

[0058] To explore the practical applications of AM-Au NCs, we investigated their fluorescence quenching ability against three commonly used dyes: fluorescein, rhodamine B, and acridine orange (AO). With increasing AM-Au NCs concentration, the fluorescence of the dyes was gradually quenched, with quenching rates reaching 91.4%, 79.3%, and 98.4%, respectively. This is attributed to the energy transfer (FRET) between the fluorescent dye and AM-Au NCs. This indicates that AM-Au NCs possess significant fluorescence quenching capabilities, making them potential quenchers for various fluorescent molecules. Notably, AM-Au NCs exhibited the strongest fluorescence quenching effect on AO. Figure 4 C), which may be attributed to the stronger interaction between AM-Au NCs and AO. Furthermore, we analyzed the quenching effect of AM-Au NCs on FAM-tagged DNA with different base sequences. Figure 4 B1-B4). FAM-tagged oligonucleotides with 33 repeating bases (A33, T33, C33) and a G-rich sequence with 4 T-base intervals (G33) were synthesized (Note: the 33 repeating G sequence cannot be obtained by chemical synthesis). AM-Au NCs effectively quenched FAM fluorescence from A33, T33, C33, and G33, and the quenching intensity increased with increasing nanoparticle concentration, which is attributed to energy transfer between FAM and AM-Au NCs. Figure 4 D). These results indicate that AM-Au NCs do indeed exhibit differentiated interactions with single-stranded DNA sequences of varying lengths, with C-rich DNA showing the strongest binding to AM-Au NCs. In other words, the binding preference order for different base pairs to AM-Au NCs is G>C>A≈T. Furthermore, the quenching efficiency of AM-Au NCs on FAM-labeled DNA is lower than that of luciferin alone (…). Figure 4 D), which may be attributed to steric hindrance caused by free single-stranded DNA molecules.

[0060] 3.3. Detection of metal ions, CD63 and exosomes based on AM-Au NCs.

[0061] 3.3.1 Detection of metal ions

[0062] We further utilized the fluorescence quenching ability of the aptamers formed by AM-Au NCs binding to fluorescent dyes (AO) and CD63 to achieve fluorescence quenching of metal ions (Al). 3+ Detection of AO and CD63. We first prepared AO-AM-Au complexes by mixing AO and AM-Au NCs. To investigate whether the AO-AM-Au complexes exhibit selective reactivity to different metal ions, we used 18 common metal ions (Al2O3, Al ... 3+ Fe 3+ Cu2+ Pb 2+ Na + Ca 2+ Hg 2+ K + Mn 2+ Cr 3+ Zn 2+ Ni 2+ Cd + Ba 2+ Be 2+ Co 2+ Bi + Mg 2+ : 5 μΜ) were selected for selective analysis. As shown in Fig. Figure 5A B, the AO-AM-Au complex showed different fluorescence responses (recovery or quenching) to the 18 metal ions after the addition of various metal ions. They showed the largest quenching effect (about 28.9%) for Al 3+ , while other interfering metal ions only led to a maximum of 8.6% fluorescence quenching or 11.9% fluorescence recovery, indicating that the AO-AM-Au complex has good selectivity in detecting Al 3+ . This can be attributed to the electrostatic attraction between the negatively charged SDBS-modified AM-Au NCs Figure 3 I) and the positively charged AO, resulting in fluorescence quenching of AO due to FRET Figure 5C ,a). Al 3+ served as a bridge between SDBS-modified AM-Au NCs and AO, further enhancing the FRET effect, leading to further quenching of the fluorescence of AO Figure 5C ,b). We further investigated the response of the AO-AM-Au complex to different concentrations of Al 3+ . In the range of 0-100 μΜ, the fluorescence intensity of the AO-AM-Au complex gradually decreased with the gradual increase of the concentration of Al 3+ ( Figure 5D ,E). Figure 5F It was shown that the fluorescence quenching rate (F0-F) / F0 had a good linear relationship with the concentration of Al 3+ in the range of 0-10 μΜ and 20-100 μΜ. The two calibration equations were y1=2.7852x1+9.5680 (correlation coefficient R 2 =0.996, LOD was 18.78 nM) and y2=0.0693x2+37.2953 (R 2 =0.999), respectively. These LODs (18.78 nM) were lower than the maximum allowable amount of Al 3+ (7.41 μΜ) in drinking water. Compared with other previously reported Al 3+Compared with optical detection methods, our proposed method has a relatively comparable linear range and even lower detection limit. According to the above results, the AO-AM-Au complex can sensitively detect Al 3+ . To evaluate the performance of the AO-AM-Au complex in real water samples, we used this complex to detect the concentration of Al 3+ ions in tap water. To avoid the influence of precipitates in water samples on the sensing system, we used a 0.22 pm membrane to filter the tap water sample. As shown in Table 2, the recovery of Al 3+ in tap water ranged from 95.36% to 116.51% at the addition levels of 5, 10, and 40 pM, with the relative standard deviation (RSD) ranging from 0.9% to 2.4%. This result indicates that this method has great potential for detecting Al 3+ in real water samples.

[0063] Figure 5 Buffer: 5 mM Tris-HAc, pH 7.0.

[0064] Table 2. Determination of Al 3+ in tap water samples

[0065]

[0066]

[0067] aNot detected.

[0068] 3.3.2 Detection of CD63 and exosomes

[0069] We also prepared CD63 aptamer-AM-Au nanoprobes by mixing CD63 aptamer with AM-Au NCs. Due to the FAM tag, the CD63 aptamer emits strong fluorescence at about 520 nm ( Figure 6A ). After the addition of AM-Au NCs, the fluorescence of the CD63 aptamer was obviously quenched (up to about 75%), which was due to the energy transfer (FRET) between FAM and AM-Au NCs. To further confirm the quenching mechanism, we studied the Stern-Volmer constant (Ksv) of AM-Au NCs for the CD63 aptamer at different temperatures. At 25 °C, the Stern-Volmer constant (K SV) was 0.0221 at 35 °C and increased with temperature. This indicated that dynamic quenching collisions occurred between the FAM-labeled CD63 aptamer and AM-AuNCs. After the addition of CD63, the CD63 aptamer-AM-Au nanoprobe showed significant fluorescence recovery, which can be attributed to the high binding affinity of the aptamer to CD63 (Kd= 58 nM). In addition, the fluorescence recovery of the CD63 aptamer-AM-Au nanoprobe for CD63 was significantly higher than that of other common interferents (CD133, BSA, lysozyme) at the same concentration, almost 8.1 times that of the interferents Figure 6C ). The CD63 aptamer-AM-Au nanoprobe was further titrated with different concentrations of CD63. The fluorescence intensity of the nanoprobe gradually increased Figure 6D ) with the increase of CD63 concentration, and the reaction time was relatively fast (about 1 min). In the ranges of 0.2-10 nM and 20-480 nM, there were two good linear relationships between the fluorescence change of the nanoprobe and the logarithm of the concentration of CD63 Figure 6D ). The two calibration equations were y1= 0.0274x1+ 0.015 (R 2 = 0.991) and y2= -0.2893x2+ 0.2735 (R 2 = 0.990). The above results showed that the CD63 aptamer-AM-Au nanoprobe could sensitively and selectively detect CD63.

[0071] To further investigate whether the CD63 aptamer-AM-Au nanoprobe could be used to detect tumor exosomes (TDEs), we purified and isolated TDEs from the supernatant of human cervical cancer SiHa. Transmission electron microscopy (TEM) images showed that the purified SiHa TDEs were spherical vesicles with a diameter of about 65 to 300 nanometers Figure 7A ). Nanoparticle tracking analysis (NTA) further revealed that the average diameter of the purified TDEs was 113.5 nanometers, and the concentration was about 1.75 x 10^5 particles / mL Figure 7A ). As shown in Figure 7B , S11A, the fluorescence intensity of the CD63 aptamer-AM-Au nanoprobe at 520 nanometers gradually increased with the increase of the concentration of TDEs from 0 to 2.18 x 10 7 particles / mL, and the reaction time was relatively fast (about 1 min). This was due to the presence of CD63 on the enriched TDEs membrane. Figure 7C It was shown that in the ranges of 0-4.35 x 10^6 particles / mL and 4.35 x 10^6-2.18 x 10 7The fluorescence of CD63 aptamer-AM-Au nanoprobe at 520 nm was linearly changed with the concentration of TDEs in the range of 0.5- 100 particle / mL. Their calibration equations were y1= 3.48 x 10 -5 x1+ 0.0787 (R 2 = 0.999) and y2= 0.52 x 10 -5 x2+ 0.3989 (R 2 = 0.923), respectively, with a detection limit of 1.69 x 10 5 particle / mL (3o rule). The detection limit and linear range of our method were close to or even better than those of reported TDEs detection methods (including fluorescence, colorimetric, electrochemical methods, Table 3). To demonstrate the practicability of our nanoprobe in real samples, we performed the spiked recovery experiments of TDEs in serum at different concentrations. The fluorescence intensity of CD63 aptamer-AM-Au nanoprobe was 12.9 times higher than that of serum itself, which indicated that the interference of serum was small. Through three parallel experiments, the recoveries of TDEs were 94.6% and 112.3% at two spiked levels (4.35 and 8.7 x 10 5 particle / mL) in serum samples, with relative standard deviations (RSDs) of 1.12% and 0.13%, respectively (Table 4). The above results indicated that CD63 aptamer-AM-Au nanoprobe had good detection ability for TDEs in serum samples.

[0073] Table 3. Comparison of detection limit and linear range of other reported TDEs.

[0074]

[0075]

[0076] a AIEgens: aggregation-induced emission luminogens

[0077] b PSMA: prostate-specific membrane antigen.

[0078] c MOF: metal-organic framework.

[0079] Table 4. Serum sample TDEs determination based on CD63 aptamer-AM-Au nanoprobe.

[0080]

[0081] 3.4. Molecular information encoding, cryptography, and steganography based on AM-Au NCs.

[0082] Molecular information technology is an emerging field that encompasses information processing, storage, and protection at the molecular level, offering a unique paradigm for information that has attracted great interest from researchers. Molecular information protection utilizes the diversity and intrinsic responsiveness of molecules for information encoding, encryption, and hiding. Figure 7A Two layers of information security are demonstrated: cryptography and steganography. Cryptography transforms secret information into an encrypted format that can only be accessed with a cryptographic key. In contrast, steganography hides information in an ordinary carrier to avoid detection, and the hidden data can be retrieved with a steganographic key. By integrating encryption and steganography, known as cryptographically steganography, a stronger level of security can be achieved. This involves encrypting data and then hiding it in a carrier, ensuring double protection, as both processes are reversible. Given the rising threat of information leaks and hacking attacks, effective information security strategies are crucial.

[0083] Here, two fluorescence sensing systems based on AM-Au NCs were developed for molecular cryptographically steganography, utilizing AO and DNA aptamer. The AO-AM-Au-based sensing system generates selective responses that can be converted into a set of 18-bit binary codes for encoding, encrypting, and hiding information. By introducing 18 metal ions (as steganographic keys), the AO-AM-Au NCs (as steganographic objects) emit selective fluorescence signals. An arbitrary threshold (-0.4) enables these fluorescence signals to be translated into an 18-bit binary string, a process similar to steganalysis, which retrieves hidden information through binary conversion. To decrypt the binary string of results, the corresponding cryptographic key is required. The decryption process is detailed in the figure, where the 18-bit binary string is segmented into shorter units, such as 12 7-bit strings or 11 8-bit strings, each of which can encode a single character. These 12 7-bit or 11 8-bit binary strings can be used to encode 12 or 11 characters, respectively. Therefore, using polyalphabetic ciphers, 7-bit binary strings (2 7 = 128) or 8-bit binary strings (2 8The 56 or 55 common characters can be encoded in a many-to-one manner using the permutations of the 256 possible combinations of the AO-AM-Au base sensing system, respectively. By applying a specific 7-bit or 8-bit cipher key (note: three example keys are used here for decryption to increase the length of the information), the hidden encrypted information in the AO-AM-Au base sensing system is decrypted, revealing two sets of plaintext. These decrypted characters are combined to generate meaningful sentences: "Where there is a will, there is a way" (this quote from Fan Ye emphasizes the importance of determination and perseverance in achieving success) and "He felt it was foolish to despair" (from Ernest Hemingway's The Old Man and the Sea, reflecting on life, courage, and persistence through the story of an old fisherman).

[0084] In addition, in the aptamer-AM-Au nanocomplex-based molecular cipher cryptosensing system, Figure 8 C), the CD63 aptamer as an information carrier (encoding data in its DNA sequence, fluorescence on) can be adsorbed on the surface of AM-Au NCs (as a nanocoating), forming an aptamer-AM-Au complex; when CD63 or TDEs as a molecular cryptic key is input into the aptamer-AM-Au, the CD63 aptamer (information carrier) is released from the AM-Au NCs, the fluorescence is restored, and the hidden information is revealed. In this system, the AM-Au NCs adsorb and hide the information DNA aptamer, and the DNA aptamer hidden AM-Au NCs (cryptographic object) specifically bind to CD63 or TDEs (molecular cryptic key) to reveal the hidden DNA, and then use the cipher key to decrypt the secret text. For example, a 32-base CD63 aptamer can use DNA hexaplex (6 bases, 4 6 =4096) or heptaplex (7 bases, 4 7= 16384) from the 5' end, by moving one base at a time. For the digital system, more bits facilitate better information concealment. For our molecular system, the “secret message” DNA aptamer can be more easily hidden in the AM-Au NCs because they have extensive surface area and the ability to bring the aptamer fluorescence almost to zero. The interaction with AM-Au NCs protects the aptamer from leakage. Even if detected by an attacker, the information remains obscure without the correct concealment key. The presence of the target CD63 or TDEs allows the decoding of the aptamer-AM-Au complex, releasing the “secret message” DNA aptamer and restoring the fluorescence. According to the corresponding rule, CD63 unlocks the CD63 aptamer (fluorescence restoration, (F-F0) / F0>0.2), revealing its DNA sequence. Even with the known DNA sequence, understanding the message still requires a specific cryptographic key. Thus, our aptamer-AM-Au fluorescence sensing system can be securely delivered to the intended recipient through certain communication channels (e.g., mailing in physical format), who should be familiar with the experimental procedure and possess a pair of keys Figure 8 C3). They can incubate the appropriate CD63 or TDEs with the aptamer-AM-Au and monitor the fluorescence response to obtain the aptamer sequence ((F-F0) / F0>0.2). With our encryption key Figure 8 C3), the hidden information in the DNA sequence can be decoded, resulting in the secret text: “aptamer DNA nanostructure” (referring to DNA self-assembly into tetrahedral structures, etc.) and “the door is open” (a spy code indicating a secure state). Moreover, the cascading cryptography and concealment system can enhance the security level. These molecular information protection techniques illustrate the versatility and flexibility of our approach. In addition, the protected molecular information can be adjusted to other types, such as different languages or musical scores. The structural diversity and natural concealment of DNA, combined with the specificity and adaptability of molecular or nanosystems, provide significant potential for information encoding, encryption, and concealment, establishing a new paradigm for information security.

[0086] 4. Conclusion

[0087] In summary, the multifunctional AM-Au nanocomposites were rapidly and conveniently synthesized for multi-analyte fluorescence sensing of metal ions, CD63, and tumor-derived exosomes, as well as molecular information encoding and protection. By mixing SDBS, AM, Au 3+With different formulations of NaBH4, we achieved AM-Au nanocomposites with tunable gold nanostructures and properties. Characterization techniques, including transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), confirmed that Au nanoparticles were dispersed in AM nanosheets and coated by SDBS, endowing the nanocomposites with extensive fluorescence quenching ability across different dyes and DNA sequences. The AM-Au nanocomposite fluorescence sensing platform combined with dyes or aptamers was developed for detecting metal ions, CD63, and tumor-derived exosomes, even in real samples. The unique selectivity and DNA sequence diversity of this system facilitate the applications of molecular-level information encoding, encryption, and hiding. Compared with previous studies, our multifunctional AM-Au nanocomposites have several advantages, including: 1) efficient, convenient, environmentally friendly, and safe preparation; 2) large surface area and mixed gold nanostructures, providing an ideal platform with unique signal conversion capabilities, including plasmonic absorption and fluorescence quenching; 3) flexible and scalable fluorescence sensing, reflecting its potential for multiple applications; 4) evidence of the molecular informatization paradigm, demonstrating the digital characteristics of nanocomposites and broad application prospects. Inspired by this work, more kinds of AM-based nanocomposites can be prepared in the future, and their new properties in catalysis, medicine, and energy can be explored. By combining with other molecular probes, such as CD63-binding peptide CPO5 (CRHSQMTVTSRL) and EpCAM-binding peptide Ep114 (KH LQCVRNICWS), it is also expected to achieve the detection of more biomarkers, such as EpCAM or CD133. This work provides a new paradigm for the preparation and multifunctional applications of two-dimensional nanocomposites and opens up new directions for the fusion of molecular sensing and informatization.

[0088] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antimonyene-gold nanocomposite material, characterized in that, Using NaBH4 as a reducing agent and SDBS as a protecting agent, it reacts with AM and Au. 3+ It is prepared by mixing at room temperature.

2. The preparation method according to claim 1, characterized in that, The combination of the four substances was assessed for product formation using color, Tyndall effect photography, and absorption spectroscopy measurements. Specifically, a stable purple solution was observed when all four components were combined (due to Au). 3+ With different concentration ratios of NaBH4, colloids a, b, and c exhibit pinkish-purple, deep purplish-red, and deep purple colors, respectively. The yellow colloid obtained when it has a characteristic absorption peak at 500-600 nm is the antimony-gold nanocomposite material prepared on the surface.

3. The preparation method according to claim 1, characterized in that, The reaction was carried out by mixing 300 μL of ultrapure water, 300 μL of 20 mM SDBS, 100 μL of 30 mg / mL AM, and 100 μL of 10 mM KAuCl4 at room temperature; after adding 200 μL of 10 mM NaBH4 and stirring for 5 seconds, the solution turned blue-purple; the final yellow colloid obtained was the antimonene-gold nanocomposite material with a concentration of 3 mg / mL.

4. An antimonene-gold nanocomposite material, characterized in that its structure consists of AM nanosheets and Au nanoparticles embedded on the surface of the AM nanosheets.

5. The antimonyene-gold nanocomposite material according to claim 4, characterized in that the diameter and density of the Au nanoparticles can be changed by altering the Au content. 3+ The concentration ratio of NaBH4 was adjusted.

6. Application of an antimonene-gold nanocomposite material in the preparation of fluorescence quenchers.

7. The application according to claim 6, characterized in that, Fluorescence quenching is achieved through energy transfer between the fluorescent dye and AM-Au NCs.

8. The use of the quencher as described in any one of claims 6-7 in the detection of metal ions.

9. The application of the antimonyene-gold nanocomposite material as described in any one of claims 1-5 in the detection of CD63 and tumor exosomes.

10. Application of antimonyene-gold nanocomposites in information encryption.

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