Water-soluble quantum dot nanomaterial, preparation method and application thereof

Abstract

The application discloses a water-soluble quantum dot nanometer material and a preparation method and application thereof, and the nanometer material comprises quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) coated on surfaces of the quantum dots. The carboxyl-terminated poly(lactic-co-glycolic acid) is used for encapsulating CsPbBr3 perovskite quantum dots, and a water-soluble perovskite nanocrystal material is prepared, which can retain high quantum yield (PLQY=88%) and water-oxygen resistance (>=30 days) and almost completely retains optical performance of the perovskite quantum dots.

Description

Technical Field

[0001] This invention belongs to the fields of materials science and biomedicine, and relates to a water-soluble quantum dot nanomaterial, its preparation method, and its application in glioma cell imaging. Specifically, it relates to a water-soluble quantum dot nanomaterial that can exist stably in an aqueous system for a long time, its preparation method, and its application in glioma cell imaging. Background Technology

[0002] Gliomas are among the most common diseases of the nervous system. Due to their invasiveness and tendency to metastasize, they exhibit high recurrence and mortality rates. Multimodal imaging combining intraoperative MRI, near-infrared fluorescence imaging, and ultrasound is a common method for guiding tumor resection. MRI provides good resolution and accuracy but lacks real-time continuous guidance and is expensive. Ultrasound is portable and low-cost, but its intraoperative imaging contrast and resolution are limited, making precise real-time detection difficult. Therefore, fluorescence imaging has significant advantages in detecting tumors during surgery, offering real-time imaging with high resolution and accuracy, and providing real-time and direct visual guidance for tumor cells.

[0003] With the increasing demand for rapid, real-time intraoperative tumor cell detection, the requirements for fluorescent biodetection probes are also becoming more stringent. Although many studies have used traditional fluorescent substances to guide the resection of gliomas, their poor fluorescence stability and low fluorescence efficiency no longer meet the requirements for high fluorescence efficiency, narrow emission, and low interference. Therefore, developing a novel nanobiodetection probe with high fluorescence intensity, narrow emission, and good biocompatibility is of great significance.

[0004] Perovskite nanocrystals, due to their size effect and quantum confinement, have become the fluorescent labeling materials with the highest quantum yield among existing materials. Furthermore, perovskite nanocrystals possess advantages such as narrow emission peaks (<20 nm), controllable emission peak positions, a wide excitation wavelength range, and ease of synthesis. However, perovskite quantum dots are intolerant to water and oxygen, severely limiting their application and development in many fields such as bioscience and medicine. Therefore, how to modify perovskite quantum dots to construct nanobioprobes that can fully utilize the material's advantages and possess good biocompatibility is an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a water-soluble quantum dot nanomaterial, its preparation method, and its application in glioma cell imaging.

[0006] The technical solution of the present invention is as follows:

[0007] A water-soluble quantum dot nanomaterial, the material comprising quantum dots and a carboxyl-terminated polylactic-co-glycolic acid copolymer (OH-PLGA-COOH) coated on the surface of the quantum dots.

[0008] According to an embodiment of the present invention, the water-soluble quantum dot nanomaterial is a nanocrystal.

[0009] According to an embodiment of the present invention, the average particle size of the quantum dots is 5 to 20 nm, for example, 10 to 15 nm; exemplaryly, the average particle size of the quantum dots is 5 nm, 8 nm, 10 nm, 12 nm, 15 nm or 20 nm.

[0010] According to an embodiment of the present invention, the average particle size of the water-soluble quantum dot nanomaterial is greater than the average particle size of the quantum dots, for example, greater than 5 nm to less than or equal to 100 nm, preferably 15 to 80 nm, more preferably 50 to 70 nm, and exemplaryly, it can be 8 nm, 10 nm, 15 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm.

[0011] According to an embodiment of the present invention, the mass ratio (mg:mg) of the quantum dots to the carboxyl-terminated polylactic acid-glycolic acid copolymer is 116:(50-200); for example, it can be 116:(60-150). For example, it can be 116:50, 116:60, 116:70, 116:80, 116:90, 116:100, 116:110, 116:120, 116:130, 116:140, 116:150, or 116:200.

[0012] According to embodiments of the present invention, the coating can be complete or partial. For example, complete coating can be achieved when the mass ratio (mg:mg) of the quantum dots to the carboxyl-terminated polylactic acid-glycolic acid copolymer is at least 116:90.

[0013] According to an embodiment of the present invention, the quantum dot may be a perovskite quantum dot, a carbon quantum dot, a cadmium quantum dot, a zinc sulfide quantum dot, or a sulfur quantum dot, etc.

[0014] For example, the perovskite quantum dot is a CsPbBr3 perovskite quantum dot.

[0015] The CsPbBr3 perovskite quantum dots are yellow under visible light and green under ultraviolet light (e.g., 365nm excitation).

[0016] According to an embodiment of the present invention, the number average molecular weight of the carboxyl-terminated polylactic acid-hydroxyacetic acid copolymer (OH-PLGA-COOH) is 10,000 to 200,000, for example 100,000 to 200,000, and for example 110,000 to 200,000.

[0017] According to an embodiment of the present invention, the carboxyl-terminated polylactic acid-glycolic acid copolymer is a random copolymer of racemic lactide (DLLA) and glycolide (GA); for example, the mass ratio of racemic lactide (DLLA) to glycolide (GA) is (50-90):(10-50), exemplarily 90:10, 75:25, 80:20, 60:40 or 50:50.

[0018] According to an embodiment of the present invention, the water-soluble quantum dot nanomaterial comprises CsPbBr3 perovskite quantum dots and a carboxyl-terminated polylactic acid-glycolic acid copolymer (OH-PLGA-COOH) coated on the surface of the CsPbBr3 perovskite quantum dots, denoted as P-PQDs.

[0019] According to an embodiment of the present invention, the water-soluble quantum dot nanomaterial has almost the same optical properties as quantum dots; for example, P-PQDs have almost the same optical properties as CsPbBr3 perovskite quantum dots.

[0020] The present invention also provides a method for preparing the above-mentioned water-soluble quantum dot nanomaterials, the method comprising the following steps: heating and reacting a carboxyl-terminated polylactic acid-glycolic acid copolymer with quantum dots to obtain the water-soluble quantum dot nanomaterials.

[0021] According to an embodiment of the present invention, the preparation method of the water-soluble quantum dot nanomaterial specifically includes the following steps:

[0022] (A1) After mixing and dissolving the raw materials for preparing quantum dots with carboxyl-terminated polylactic acid-glycolic acid copolymer in a solvent, an organic ligand is added to form a stable solution;

[0023] (A2) The stable solution described in step (A1) is added to the antisolvent and heated to react. Water-soluble quantum dot nanomaterials are precipitated by the antisolvent supersaturation method to prepare water-soluble quantum dot nanomaterials.

[0024] According to an embodiment of the present invention, when the quantum dot is a CsPbBr3 perovskite quantum dot, the raw materials for preparing the quantum dot are, for example, CsBr and PbBr2.

[0025] The CsPbBr3 perovskite quantum dots can be prepared using methods known in the art.

[0026] According to an embodiment of the present invention, in step (A1), the mixing order of the raw materials for preparing quantum dots and the carboxyl-terminated polylactic acid-glycolic acid copolymer is not limited. For example, the raw materials for preparing quantum dots and the carboxyl-terminated polylactic acid-glycolic acid copolymer can be added to the solvent at the same time, or the raw materials for preparing quantum dots can be added to the solvent first, and then the carboxyl-terminated polylactic acid-glycolic acid copolymer can be added to the solvent.

[0027] According to an embodiment of the present invention, in step (A1), the ratio (mg:mg) of the sum of the masses of the raw materials for preparing quantum dots to the mass of the carboxyl-terminated polylactic acid-hydroxyacetic acid copolymer (OH-PLGA-COOH) is 116:(50-200), preferably 116:(60-150).

[0028] According to an embodiment of the present invention, in step (A1), the mass-volume ratio of the carboxyl-terminated polylactic acid-hydroxyacetic acid copolymer to the solvent is (5-30) mg:1 mL, for example, 5 mg:1 mL, 10 mg:1 mL, 15 mg:1 mL, 18 mg:1 mL, 20 mg:1 mL, 25 mg:1 mL or 30 mg:1 mL.

[0029] According to an embodiment of the present invention, in step (A1), the solvent may be selected from one or both of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0030] According to an embodiment of the present invention, in step (A1), the organic ligand may be selected from at least one of oleic acid, oleylamine, and octylamine, for example, a mixture of oleic acid and oleylamine in any proportion.

[0031] Preferably, the volume ratio of the organic ligand to the solvent is (0.5-5):10, for example (1-3):10, such as 0.5:10, 1:10, 1.5:10, 2:10, 2.5:10, 3:10, 4:10 or 5:10.

[0032] According to an embodiment of the invention, step (A1) is carried out under anhydrous and oxygen-free conditions. Preferably, it is carried out in an inert atmosphere, such as nitrogen or argon.

[0033] According to an embodiment of the present invention, in step (A2), the antisolvent is selected from at least one of toluene, chlorobenzene, and n-hexane.

[0034] According to an embodiment of the present invention, step (A2) includes: first, adding the stable solution described in step (A1) dropwise to the antisolvent to obtain a water-soluble quantum dot nanomaterial solution; heating the reaction, and after the reaction is completed, collecting the precipitate by high-speed centrifugation and ultrasonically dispersing it in water to obtain water-soluble quantum dot nanomaterials.

[0035] Preferably, the volume ratio of the stable solution to the antisolvent is (0.1-5):10, for example (0.5-3):10.

[0036] Preferably, the dripping is done slowly, drop by drop, for example, at a dripping rate of 6 to 12 μL / s, such as 6 μL / s, 8 μL / s, 10 μL / s, or 12 L / s.

[0037] Preferably, the addition is carried out under conditions of vigorous stirring and antisolvent removal.

[0038] Preferably, the water-soluble quantum dot nanomaterial solution is added to an excess of antisolvent, heated and stirred to react, and the water-soluble quantum dot nanomaterial is precipitated.

[0039] For example, the stirring time is 5 to 10 hours, such as 5 hours, 7 hours, 8 hours, or 10 hours. For example, the reaction temperature is 30 to 60 degrees Celsius, such as 40 to 50 degrees Celsius, such as 30, 40, 42, 45, 48, 50, or 60 degrees Celsius.

[0040] According to an embodiment of the present invention, the preparation method of the water-soluble quantum dot nanomaterial further includes:

[0041] (A3) Separate the water-soluble quantum dot nanomaterials described in step (A2), dry the precipitate, and obtain solid water-soluble quantum dot nanomaterials.

[0042] According to an embodiment of the present invention, the preparation method of the water-soluble quantum dot nanomaterial further includes:

[0043] (A4) Disperse the solid water-soluble quantum dot nanomaterials obtained in step (A3) in water to obtain a water-soluble quantum dot nanomaterial solution.

[0044] The present invention also provides water-soluble quantum dot nanomaterials prepared by the above method.

[0045] According to the present invention, the water-soluble quantum dot nanomaterial is a solid water-soluble quantum dot nanomaterial or a water-soluble quantum dot nanomaterial solution.

[0046] Specifically, it is an aqueous solution of water-soluble quantum dot nanomaterials, and more specifically, an aqueous solution of water-soluble quantum dot nanocrystals.

[0047] The present invention also provides the application of the above-mentioned water-soluble quantum dot nanomaterials in the preparation of nanoprobes or reagent kits for medical diagnosis.

[0048] For example, the nanoprobe can be a fluorescent biodetection probe or a cell imaging probe.

[0049] The present invention also provides a nanoprobe comprising the water-soluble quantum dot nanomaterial.

[0050] According to an embodiment of the present invention, the nanoprobe is a biomaterial labeled with the water-soluble quantum dot nanomaterial.

[0051] According to embodiments of the present invention, the biomaterial may be selected from one, two, or more of antibodies, aptamers, polypeptides, etc. Exemplarily, the biomaterial is a polypeptide; for example, a chlortoxin polypeptide.

[0052] According to an embodiment of the present invention, the nanoprobe can generate strong fluorescence in the range of 500 to 540 nm when excited at 365±5 nm, and the strongest fluorescence, i.e., green light, is generated at 515±5 nm.

[0053] According to an exemplary embodiment of the present invention, the nanoprobe is a chlorine toxin polypeptide labeled with water-soluble perovskite nanomaterials P-PQDs, formed by the electrostatic interaction between P-PQDs and the chlorine toxin polypeptide.

[0054] According to an embodiment of the present invention, the mass ratio of water-soluble quantum dot nanomaterials to biomaterials is (10-50):1, exemplarily 10:1, 15:1, 20:1, 25:1, 30:1, 40:1 or 50:1.

[0055] According to an embodiment of the present invention, the average particle size of the nanoprobe is 20 to 100 nm, and is exemplary to be 20 nm, 30 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm.

[0056] The present invention also provides a method for preparing the above-mentioned nanoprobe, the method comprising the following steps: coupling water-soluble quantum dot nanomaterials and biological materials to prepare the nanoprobe.

[0057] According to an embodiment of the present invention, the preparation method includes the following steps: mixing water-soluble quantum dot nanomaterials with biomaterials, and obtaining the nanoprobe through strong charge difference electrostatic interaction;

[0058] The water-soluble nanomaterials and biomaterials have the meanings described above.

[0059] According to an embodiment of the present invention, the coupling is carried out in the presence of a solvent. Specifically, the solvent may be an ultrapure aqueous solution (e.g., pH = 6.42).

[0060] According to an embodiment of the present invention, the mass ratio of the biomaterial to the water-soluble quantum dot nanomaterial is 1:(10-50), for example, 1:10, 1:15, 1:20, 1:25, 1:30, 1:40 or 1:50.

[0061] According to an embodiment of the present invention, the nanoprobe can also be cryogenically stored in the preparation method of the nanoprobe. For example, the cryogenic storage temperature is 1 to 5°C, such as 1°C, 2°C, 3°C, 4°C, or 5°C.

[0062] The present invention also provides nanoprobes prepared by the above method.

[0063] The present invention also provides a kit comprising the nanoprobe.

[0064] This invention also provides applications of the above-mentioned water-soluble quantum dot nanomaterials, nanoprobes, or kits in medical testing, medical diagnosis, and other fields.

[0065] Preferably, the medical test can be cell imaging or biological detection. Preferably, for example, glioma cell imaging.

[0066] According to embodiments of the present invention, the nanoprobe or kit can recognize at least one of the following target analytes: antibodies, aptamers, peptides, antigens, target molecules, proteases, etc. For example, peptides, such as chloramphenicol peptides, etc.

[0067] The present invention also provides a method for identifying the target analyte using the above-mentioned nanoprobe or kit, the method comprising: contacting the nanoprobe with the target analyte and identifying it by fluorescence detection.

[0068] According to the present invention, the excitation wavelength for fluorescence detection is 365 nm to 450 nm.

[0069] The beneficial effects of this invention are:

[0070] 1. This invention utilizes carboxyl-terminated polylactic acid-glycolic acid copolymer (OH-PLGA-COOH) to encapsulate CsPbBr3 perovskite quantum dots to prepare water-soluble perovskite nanocrystalline materials. While retaining a high quantum yield (PLQY = 88%), it can also maintain water and oxygen resistance (≥30 days) and almost completely retain the optical properties of perovskite quantum dots.

[0071] 2. The product of this invention uses biodegradable polylactic acid-glycolic acid copolymer to coat quantum dot materials to prepare biological nanoprobes, which not only retains the high fluorescence intensity and narrow emission performance of quantum dots, but also endows them with good biocompatibility, non-toxicity and environmental protection properties.

[0072] 3. The water-soluble quantum dot nanocrystal bio-nano probe of the present invention can be used in the medical field for the simultaneous detection of multiple analytes, and can avoid false negative results caused by the crossover of emission peaks of fluorescent substances, thereby improving the reliability of detection. It has universality and can realize the simultaneous detection of multiple target analytes, which greatly meets the needs of modern biotechnology and medical testing, and has important significance in the field of medical diagnosis and treatment.

[0073] 4. The water-soluble quantum dot nanomaterials of this invention achieve electrostatic interaction through a simple strong potential difference, enabling simple and rapid coupling of biomaterials, eliminating the need for cumbersome coupling reactions. Furthermore, the prepared reagent kit is low-cost, easy to operate, and readily commercializable.

[0074] 5. The novel biological nanoprobe constructed based on water-soluble quantum dot materials of the present invention (taking chlorine toxin nanoprobe as an example) can specifically identify glioma cells, thereby distinguishing tumor tissue, adjacent tissue and normal tissue, and realizing real-time and direct visual guidance for tumor resection. Attached Figure Description

[0075] Figure 1 Transmission electron microscopy image of the PQDs quantum dots prepared in Example 1.

[0076] Figure 2 This is a transmission electron microscope (TEM) image of the P-PQDs perovskite nanocrystals from Example 1.

[0077] Figure 3 The image shows the fluorescence imaging of P-PQDs perovskite nanocrystals from Example 1 under excitation at 420–450 nm.

[0078] Figure 4 Quantum yield diagrams for the PQDs prepared in Example 1 and the P-PQDs perovskite nanocrystals prepared in Example 1.

[0079] Figure 5 The image shows the PL spectrum of the P-PQDs perovskite nanocrystals from Example 1.

[0080] Figure 6 The fluorescence emission spectra of the P-PQDs nanocrystals in Example 1 and the Probe-PQDs nanoprobes in Example 2 are shown.

[0081] Figure 7 The zeta potential diagrams are shown for the P-PQDs quantum dot nanomaterials in Example 1, the chloramphenicol peptide (CTX), and the Probe-PQDs in Example 2.

[0082] Figure 8 This is a fluorescence imaging image of Probe-PQDs nanoprobes recognizing glioma 251 cells and HA cells in Example 3. Detailed Implementation

[0083] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0084] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0085] The carboxyl-terminated polylactic acid-glycolic acid copolymer (OH-PLGA-COOH) used in the following examples was purchased from Jinan Daigang Bioengineering Co., Ltd., with a number average molecular weight of 110,000 and a mass percentage of DLLA:GA of 50:50.

[0086] Preparation Example 1

[0087] The preparation steps for PQDs (perovskite quantum dots) are as follows:

[0088] (1) Dissolve 42.5 mg CsBr and 73.4 mg PbBr2 in 5 mL of N,N-dimethylformamide (DMF) solvent. After complete dissolution, add 0.5 mL of oleic acid and 0.25 mL of oleylamine to stabilize the solution.

[0089] (2) Take 500 μL of the above solution, place it in a glove box, and slowly add it dropwise (at a rate of 10 μL / s) to 10 mL of vigorously stirred toluene solution under N2 atmosphere protection to obtain PQDs perovskite quantum dot solution.

[0090] (3) The prepared PQDs perovskite quantum dots were centrifuged at 10000 r / min for 20 min to separate the supernatant, which is the purified PQDs perovskite quantum dot solution. The solution is clear green.

[0091] Figure 1 The image shows a transmission electron microscope (TEM) image of the prepared PQDs perovskite quantum dots. It can be seen from the image that the particle size of the PQDs perovskite quantum dots is about 12 nm, which matches the size of CsPbBr3 quantum dots.

[0092] Example 1: P-PQDs water-soluble perovskite nanocrystals

[0093] To achieve a hydrophobic effect, based on Preparation Example 1, a hydrophobic end-carboxyl polylactic acid-glycolic acid copolymer (OH-PLGA-COOH) was coated onto the surface of highly fluorescent perovskite quantum dots to form water-soluble perovskite nanocrystals P-PQDs. The steps are as follows:

[0094] (1) Dissolve 42.5 mg CsBr and 73.4 mg PbBr2 with 90 mg carboxyl-terminated polylactic acid-glycolic acid copolymer (OH-PLGA-COOH) in 5 mL of N,N-dimethylformamide (DMF) solvent. After complete dissolution, add 0.5 mL of oleic acid and 0.25 mL of oleylamine to form a stable solution.

[0095] (2) Take 750 μL of the above solution and slowly add it dropwise (at a rate of 10 μL / s) to 15 mL of vigorously stirred toluene solution. Stir at 60 °C for 8 h to allow the reaction to be complete and precipitate water-soluble perovskite nanocrystals P-PQDs.

[0096] (3) P-PQDs perovskite nanocrystals were separated and purified. They were centrifuged at 10000 r / min for 20 min. The precipitate was dried in an oven at 60℃ for 1 h to obtain a dark yellow powder. The powder turned green under 365nm ultraviolet light.

[0097] (4) Disperse the powder in water and store the water-soluble perovskite nanocrystals P-PQDs at room temperature.

[0098] Figure 2 This is a transmission electron microscope (TEM) image of the water-soluble P-PQDs perovskite nanocrystals prepared in Example 1. From... Figure 2 As can be seen, the average particle size of the P-PQDs perovskite nanocrystals is 50 nm, which is larger than that of Preparation Example 1. This indicates that the end-carboxyl polylactic acid-glycolic acid copolymer coats multiple PQDs quantum dots into a whole morphology, and the coating effect is good.

[0099] Figure 3 The image shows the fluorescence imaging of P-PQDs perovskite nanocrystals in Example 1 under excitation at 420–450 nm. Under excitation at 420–450 nm, the P-PQDs perovskite nanocrystals appear green.

[0100] Figure 4 To obtain quantum yield diagrams for the PQDs of Example 1 and the P-PQDs perovskite nanocrystals of Example 1, the excitation wavelength was measured at 365.4 nm. The coated P-PQDs perovskite nanocrystals maintained a high quantum yield of 88%.

[0101] Figure 5 The image shows the PL spectrum of P-PQDs perovskite nanocrystals from Example 1. Figure 5 In the figure, the curves from top to bottom represent 1, 2, 3, ... 30 days, respectively. The figure shows that P-PQDs perovskite nanocrystals maintain a high fluorescence intensity within 30 days in an aqueous system and when exposed to air.

[0102] Example 2: Preparation of water-soluble perovskite nanocrystal bio-nanoprobes

[0103] To further couple hydrophobic perovskite quantum dot nanocrystals with biomaterials to construct novel nanobioprobes, based on Example 1, the high positive charge properties of the perovskite quantum dot surface are utilized to connect with negatively charged biomaterials through electrostatic interactions between positive and negative charges, thus constructing a water-soluble perovskite nanocrystal probe. The specific implementation steps are as follows:

[0104] (1) Chlorine toxin polypeptide (CTX) was dissolved in ultrapure water (pH=6.42) and its solution concentration was prepared to be 10 mg / mL.

[0105] (2) Take 1 mL of P-PQDs solution with a concentration of 0.1 mg / mL in Example 1 and mix it with 10 μL of chloramphenicol peptide with a concentration of 10 mg / mL. Vortex for 30 seconds to mix it evenly. Store the prepared Probe-PQDs nanoprobe solution at 4°C.

[0106] Figure 6 P-PQDs (i.e., P-PQDs) of the aqueous solution system in Example 1 Figure 6 PQDs-Water and the nanoprobe-PQDs in Example 2 (i.e., PQDs-Water) Figure 6 The fluorescence emission spectrum of the Probe-Water nanoprobes is shown in the figure. As can be seen from the figure, the Probe-PQDs nanoprobes exhibit a slight blue shift compared to P-PQDs. This is because the size of the P-PQDs changes due to the connection of the biological material, resulting in a slight change in their corresponding spectrum. It can also be seen that the Probe-PQDs nanoprobes almost completely retain the original optical properties of the P-PQDs.

[0107] Figure 7 The zeta potential diagrams are for the P-PQDs quantum dot nanomaterials in Example 1, and the Probe-PQDs and chloramphenicol peptide (CTX) in Example 2.

[0108] Example 3: Nanoprobes identify glioma 251 cells

[0109] After constructing the biological nanoprobe, the recognition function was verified using the nanoprobe from Example 2. Based on Example 2, conventional experimental methods in biological experiments were used to verify the probe's recognition function. In this example, DAPI was used, and the nanoprobe P-PQDs prepared in Example 2 were used to label chloramphenicol peptides. The target analytes were glioma U251 cells and HA cells.

[0110] (1) U251 cells and HA cells were mixed at a density of 1×10⁻⁶ cells per well. 5 Cells were seeded at a density of 1,000 cells in confocal dishes and cultured in a CO2 incubator at 37°C.

[0111] (2) Remove the confocal dish and rinse the cells three times with PBS (0.01M, pH=7.3).

[0112] (3) Add 2 mL of 4% paraformaldehyde to fix for 15 min, and then rinse the cells three times with PBS (0.01 M, pH = 7.3).

[0113] (4) Add 2 mL of goat serum working solution to block for 30 min, and then rinse the cells three times with PBS (0.01 M, pH 7.3).

[0114] (5) Add 1 mL of the prepared 0.1 mg / mL Probe-PQDs probe solution and identify at room temperature for 1 h.

[0115] (6) The probe solution was recovered and the cells were washed again with PBS (0.01M, pH=7.3) 4 to 6 times.

[0116] (7) Counterstain cell nuclei with DAPI (1 mg / ml), incubate in the dark for 15 min, and wash cells 4-6 times with PBS (0.01 M, pH 7.3).

[0117] (8) Observe the confocal microscope. Excitement is achieved through dual channels at 405nm and 488nm. Figure 8 The image shows a confocal fluorescence image validating the recognition of Probe-PQDs nanoprobes with U251 glioma cells and HA cells in Example 3. Dual-channel excitation at 405nm and 488nm was used. The 405nm channel corresponds to the DAPI channel; the 488nm channel corresponds to Probe-PQDs. Merging and statistical analysis were performed. The image clearly shows that the Probe-PQDs nanoprobes recognize U251 glioma cells, but hardly recognize HA cells, which express almost no DAPI. This demonstrates that the nanoprobes of this application can distinguish between tumor tissue, adjacent normal tissue, and normal tissue, enabling real-time and direct visual guidance for tumor resection.

[0118] In this invention, by replacing the chloramphenicol polypeptide in Example 2 with an aptamer or antibody, a nanoprobe conjugated with perovskite nanocrystals and an aptamer or antibody can also be obtained, and the obtained nanoprobe also has a specific recognition function.

[0119] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water-soluble quantum dot nanomaterial, characterized in that, The material comprises quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) covering the surface of the quantum dots; The number average molecular weight of the carboxyl-terminated poly(lactic-co-glycolic acid) is 100000-200000; The water-soluble quantum dot nanomaterial is prepared by a method comprising the following steps: (A1) After the raw material for preparing quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) are mixed and dissolved in a solvent, an organic ligand is added to form a stable solution; (A2) The stable solution in step (A1) is added to an anti-solvent, heated and reacted, and water-soluble quantum dot nanomaterial is precipitated by an anti-solvent supersaturation method to prepare the water-soluble quantum dot nanomaterial; The quantum dots are CsPbBr3 perovskite quantum dots; and the raw material for preparing quantum dots is CsBr and PbBr2.

2. The water-soluble quantum dot nanomaterial of claim 1, wherein, The water-soluble quantum dot nanomaterial is a nanocrystal.

3. The water-soluble quantum dot nanomaterial of claim 1, wherein, The average particle size of the quantum dots is 5-20 nm.

4. The water-soluble quantum dot nanomaterial of claim 1, wherein, The average particle size of the water-soluble quantum dot nanomaterial is greater than the average particle size of the quantum dots, and is greater than 5 nm and less than or equal to 100 nm.

5. The water-soluble quantum dot nanomaterial of claim 1, wherein, The mass ratio of the quantum dots to the carboxyl-terminated poly(lactic-co-glycolic acid) is 116: (50-200).

6. A method for preparing the water-soluble quantum dot nanomaterials according to any one of claims 1-5, characterized in that, The preparation method specifically comprises the following steps: (A1) After the raw material for preparing quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) are mixed and dissolved in a solvent, an organic ligand is added to form a stable solution; (A2) The stable solution in step (A1) is added to an anti-solvent, heated and reacted, and water-soluble quantum dot nanomaterial is precipitated by an anti-solvent supersaturation method to prepare the water-soluble quantum dot nanomaterial.

7. A nanoprobe, characterized in that, The nanoprobes comprise the water-soluble quantum dot nanomaterial according to any one of claims 1-5; The nanoprobes are biomaterials labeled by the water-soluble quantum dot nanomaterial; The biomaterials are selected from one, two or more of antibodies, aptamers and polypeptides.

8. The method of claim 7, wherein the nanoprobe is prepared by the steps of: The preparation method comprises coupling the water-soluble quantum dot nanomaterial and the biomaterials to prepare the nanoprobes.

9. A kit characterized in that, The kit comprises the nanoprobes according to claim 7.

10. Use of the water-soluble quantum dot nanomaterial of any one of claims 1-5, the nanoprobe of claim 7, or the kit of claim 9, wherein the use is for the treatment of cancer. Applied to imaging of brain glioma cells for non-diagnostic purposes.

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