A preparation method of water-soluble quantum dots and its application

Abstract

The present invention discloses a method for preparing water-soluble quantum dots. The preparation method uses a surfactant solution to coat oil-soluble quantum dots, retaining the fluorescence of the oil-soluble quantum dots, and uses water-soluble polymer ligands (polyvinyl alcohol and polyvinyl pyrrolidone) to complete functional modification, thereby solving the problems of easy quenching of quantum dot fluorescence, inability of nanoparticles to stably agglomerate, and prone to nonspecific adsorption, resulting in low detection sensitivity. When the water-soluble quantum dots prepared by the preparation method of the present invention are used for biomarker detection, they can be directly dissolved in water, and the fluorescent group is stable, can stably agglomerate and specifically adsorb biological targets; therefore, the immunochromatographic test strips prepared using the water-soluble quantum dots can simply and stably adsorb drug antibodies, thereby improving detection sensitivity, with the detection sensitivity for morphine reaching 0.1 ng / mL.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum dot synthesis, and in particular to a preparation method of water-soluble quantum dots and applications thereof. Background Art

[0002] In recent years, the efficient labeling and visualization of macromolecular proteins has been a hot topic in clinical disease diagnosis and basic biomedical research. Among currently available fluorescent labeling materials, quantum dots (QDs) offer the most exceptional fluorescence properties. They not only exhibit high fluorescence intensity, a narrow and highly symmetrical half-width (FWHM) emission peak, a larger Stoke shift, and enhanced resistance to photobleaching, but also their emission wavelength can be effectively controlled by the material's composition and particle size, allowing simultaneous generation of multiple emission wavelengths under the same excitation light. Therefore, QDs hold great potential for application in bioimaging and disease diagnosis.

[0003] Currently, high-temperature organic solvents such as oleic acid and oleylamine are used as surface ligands, and high-temperature thermal decomposition, high-temperature coprecipitation, and solvothermal methods can be used to synthesize high-quality, uniformly sized nanoparticles with strong luminescence. After isolation and purification, these nanoparticles disperse well in non-polar solutions such as cyclohexane, but are typically extremely hydrophobic, making them unsuitable for direct labeling of large proteins.

[0004] For biological applications, these nanoparticles require surface modification and functionalization to ensure uniform dispersion in an aqueous phase. Currently, methods for transferring nanoparticles synthesized in an oil phase to an aqueous phase primarily include ligand exchange, ligand oxidation, amphiphilic ligand coating, and silica coating. However, the resulting nanoparticles exhibit fluorescence quenching in biological detection and in vivo imaging applications, lack stable aggregation, and are prone to nonspecific adsorption. Consequently, their performance in applications is unsatisfactory. Currently, quantum dot test strips have a sensitivity of 0.5 ng / mL for drug (morphine) detection (CN110470843A).

[0005] Therefore, there is an urgent need to prepare a new type of water-soluble quantum dots to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a method for preparing water-soluble quantum dots and applications thereof.

[0007] The first object of the present invention is to provide a method for preparing water-soluble quantum dots.

[0008] The second object of the present invention is to provide water-soluble quantum dots prepared by the above preparation method.

[0009] The third object of the present invention is to provide a reagent for detecting drugs.

[0010] The fourth object of the present invention is to provide an immunochromatographic test strip.

[0011] The fifth object of the present invention is to provide the use of the above-mentioned water-soluble quantum dots, reagents and / or immunochromatographic test strips in hair drug detection.

[0012] In order to achieve the above object, the present invention is implemented through the following scheme:

[0013] A method for preparing water-soluble quantum dots comprises the following steps:

[0014] S1. The oil-soluble quantum dots are mixed with the dispersion and mixed thoroughly to obtain a first liquid system;

[0015] The solute of the dispersion includes a surfactant, and the solvent is an oily solvent;

[0016] S2. The first liquid system obtained in step S1 is mixed with a water-soluble polymer ligand solution to obtain a second liquid system;

[0017] S3. Removing the oily solvent and the excess water-soluble polymer ligand solution from the dispersion in the second liquid system obtained in step S2 to obtain water-soluble quantum dots.

[0018] Oil-soluble quantum dots, also known as hydrophobic quantum dots, refer to quantum dots that are coated with hydrophobic ligands on the surface of ZnCdSe / ZnS quantum dots and can be uniformly dispersed in non-polar organic solvents (such as hexane, toluene, and chloroform).

[0019] Surfactants are substances with fixed hydrophilic and lipophilic groups that can be aligned on the surface of a solution and significantly reduce surface tension. The surfactants used in the present invention possess hydrophobic carbon chains whose lengths match the carbon chains on the surface of nanoparticles synthesized in the oil phase. This prevents fluorescence quenching caused by aggregation of the nanoparticles by maintaining the distance and hydrophobic state between the luminescent cores. Furthermore, by encapsulating oil-soluble quantum dots within the hydrophobic structure of surfactant micelle aggregates, the fluorescence of the particles with oil-phase ligands is effectively retained. The surfactants used in the present invention are preferably hexadecyltrimethylammonium bromide, sodium lauryl sulfate, and / or sodium lauryl sulfonate.

[0020] Preferably, the oil-soluble quantum dots in step S1 are oil-soluble quantum dots dispersed, dissolved and washed with n-hexane.

[0021] Preferably, the dispersion in step S1 is a solution of hexadecyltrimethylammonium bromide, sodium dodecyl sulfate and / or sodium dodecyl sulfonate using dichloromethane as a solvent.

[0022] More preferably, the mass concentration of the dispersion is 0.05% to 1%.

[0023] Preferably, the water-soluble polymer ligand in step S2 is a polyvinyl alcohol aqueous solution and a polyvinyl pyrrolidone aqueous solution;

[0024] The mass concentration of the polyvinyl alcohol aqueous solution is 0.1% to 1%; the mass concentration of the polyvinyl pyrrolidone aqueous solution is 0.2% to 1%.

[0025] The polyvinyl alcohol has the characteristics of multiple hydroxyl groups, being soluble in water but insoluble in organic solvents, and is used for precipitating and separating quantum dot materials. On the one hand, it can maintain the long-term stability of the quantum dot materials in the aqueous solution, and on the other hand, it can use organic solvents such as methanol and ethanol to aggregate and precipitate the quantum dot materials in the aqueous phase, avoiding long-term high-speed centrifugation to separate and purify the quantum dot materials.

[0026] The polyvinyl pyrrolidone has the physical property of efficiently adsorbing carboxyl groups, can adsorb polypeptides and proteins, and quickly complete the biological labeling of water-soluble quantum dots.

[0027] More preferably, the volume ratio of the polyvinyl alcohol aqueous solution, the polyvinyl pyrrolidone aqueous solution and the dispersion in step S1 is 10-100:20-100:100.

[0028] Preferably, the removal of the oily solvent in the dispersion in the second liquid system obtained in step S2 in step S3 is specifically carried out by ultrasonic removal, and / or fully mixing the second liquid system obtained in step S2 with water, separating the oil phase and the water phase, and then discarding the oil phase.

[0029] The present invention also seeks to protect the water-soluble quantum dots prepared by any of the above-mentioned preparation methods.

[0030] The present invention also seeks protection for a reagent for detecting drugs, wherein the reagent is the above-mentioned water-soluble quantum dots coupled with drug antibodies;

[0031] The drug antibodies are morphine antibodies, methamphetamine antibodies and / or ketamine antibodies.

[0032] An immunochromatographic test strip comprises a sample pad, a conjugation pad, an immunochromatographic reaction membrane and a water-absorbing pad arranged in sequence on a bottom plate;

[0033] The conjugate pad is coated with the above reagents.

[0034] Preferably, the coupling method is physical adsorption.

[0035] Preferably, the preparation method of the detection reagent is specifically as follows:

[0036] S1. The water-soluble quantum dots and the drug antibody solution are thoroughly mixed to obtain mixed quantum dots;

[0037] S2. Adding a blocking agent to the mixed quantum dots obtained in step S1 and allowing the mixture to react fully until the excess adsorption sites of the water-soluble quantum dots are completely blocked to obtain blocked quantum dots;

[0038] The blocking agent is a glycine aqueous solution with a mass concentration of 10% to 20%;

[0039] S3. The blocked quantum dots obtained in step S2 were mixed with anhydrous ethanol and centrifuged at 4000 rpm for 3 to 10 min. The precipitate was collected by solid-liquid separation and dispersed in a buffer solution to obtain a detection reagent.

[0040] The buffer is PBS buffer, HEPES buffer, MOPSO buffer and / or DIPSO buffer.

[0041] Specifically, the above-mentioned detection reagent, chitosan and surfactant are evenly mixed and then sprayed on a conjugation pad carrier to obtain a conjugation pad with water-soluble quantum dots coupled with drug antibodies; the conjugation pad carrier is a glass fiber pad.

[0042] After spraying, the detection reagent is bound to the glass fiber mat through electrostatic adsorption and hydrophobic interactions. Surfactants can help disrupt these hydrophobic interactions, effectively facilitating the reconstitution and release of the detection reagent. Common surfactants such as Tween-20, surfactant S6, and / or surfactant S9 can be used.

[0043] The present invention also seeks to protect the use of the above-mentioned water-soluble quantum dots and / or the above-mentioned immunochromatographic test strips in hair drug detection.

[0044] Preferably, the drug is morphine, methamphetamine and / or ketamine.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention provides a method for preparing water-soluble quantum dots. The preparation method uses a surfactant solution to coat oil-soluble quantum dots, retaining the fluorescence of the oil-soluble quantum dots, and uses water-soluble polymer ligands (polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP)) to complete functional modification, thereby solving the problems of easy quenching of quantum dot fluorescence, inability of nanoparticles to stably agglomerate, and prone to nonspecific adsorption, resulting in low detection sensitivity. When the water-soluble quantum dots prepared by the preparation method of the present invention are used for biomarker detection, they can be directly dissolved in water, and the fluorescent groups are stable, can stably agglomerate, and specifically adsorb biological targets; therefore, the immunochromatographic test strips prepared using the water-soluble quantum dots can simply and stably adsorb drug antibodies, thereby improving detection sensitivity, with the detection sensitivity for morphine reaching 0.1 ng / mL. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The figure is a flow chart for the preparation of water-soluble quantum dots;

[0048] Figure 2 It is a structural diagram of the immunochromatographic test paper card;

[0049] Figure 3 This is the test result diagram of the immunochromatographic reagent strip. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below with reference to the accompanying drawings and specific examples. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available unless otherwise specified.

[0051] The oil-soluble quantum dots described in the examples of the present invention were purchased from Wuhan Jiayuan Biotechnology Co., Ltd. with the product number Q1605. The standard package is 30 mg of powdered quantum dots dispersed in 10 mL of n-hexane solvent.

[0052] Example 1 Preparation of water-soluble quantum dots

[0053] The preparation process of water-soluble quantum dots is as follows Figure 1 shown.

[0054] 1. Oil-soluble quantum dots pretreatment:

[0055] Take 200 μL of oil-soluble quantum dots (dispersed in n-hexane, solid content of 3 mg / mL) and place it in a 2 mL EP tube, add 1800 μL of anhydrous ethanol, shake for 3 minutes to mix, then centrifuge at 16000 rpm for 10 minutes, remove the supernatant, and obtain pretreated oil-soluble quantum dots.

[0056] 2. Construction of microemulsion system:

[0057] The pretreated oil-soluble quantum dots obtained in step 1 were thoroughly mixed with 100 μL of a 0.05% cetyltrimethylammonium bromide (CTAB) solution using dichloromethane as a solvent, and the mixture was shaken for 3 minutes to obtain a first liquid system;

[0058] Then, the first liquid system, 100 μL of a 0.2% polyvinyl pyrrolidone (PVP) aqueous solution, and 100 μL of a 0.1% polyvinyl alcohol (PVA) aqueous solution were mixed and shaken for 10 minutes to mix evenly, thereby obtaining a second liquid system.

[0059] 3. Removal of solvent and excess ligand:

[0060] Add 300 μL of water to the second liquid system obtained in step 2, shake for 10 minutes to mix, and ultrasonicate to remove the dichloromethane solvent; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate, and disperse the precipitate in 700 μL of ultrapure water; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate 1, and obtain water-soluble quantum dots 1. Dissolve the water-soluble quantum dots 1 in 500 μL of ultrapure water for later use.

[0061] Example 2 Preparation of water-soluble quantum dots

[0062] 1. Oil-soluble quantum dots pretreatment:

[0063] 200 μL of oil-soluble quantum dots (dispersed in n-hexane) were placed in a 2 mL EP tube, 1800 μL of anhydrous ethanol was added, and the mixture was shaken for 3 min to mix. The mixture was then centrifuged at 16,000 rpm for 10 min, and the supernatant was removed to obtain pretreated oil-soluble quantum dots.

[0064] 2. Construction of microemulsion system:

[0065] The pretreated oil-soluble quantum dots obtained in step 1 were thoroughly mixed with 100 μL of a 0.5% sodium lauryl sulfate solution using dichloromethane as a solvent, and the mixture was shaken for 3 minutes to obtain a first liquid system 1;

[0066] Then, the first liquid system 1, 50 μL of a 0.5% polyvinyl pyrrolidone (PVP) aqueous solution, and 60 μL of a 0.7% polyvinyl alcohol (PVA) aqueous solution were mixed and shaken for 10 minutes to mix evenly, thereby obtaining a second liquid system 1.

[0067] 3. Removal of solvent and excess ligand:

[0068] Add 300 μL of water to the second liquid system 1 obtained in step 2, shake for 10 minutes to mix, and ultrasonicate to remove the dichloromethane solvent; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate, and disperse the precipitate in 700 μL of ultrapure water; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate 1, and obtain water-soluble quantum dots 2. Dissolve the water-soluble quantum dots 2 in 500 μL of ultrapure water for later use.

[0069] Example 3 Preparation of Water-Soluble Quantum Dots

[0070] 1. Oil-soluble quantum dots pretreatment:

[0071] 200 μL of oil-soluble quantum dots (dispersed in n-hexane) were placed in a 2 mL EP tube, 1800 μL of anhydrous ethanol was added, and the mixture was shaken for 3 min to mix. The mixture was then centrifuged at 16,000 rpm for 10 min, and the supernatant was removed to obtain pretreated oil-soluble quantum dots.

[0072] 2. Construction of microemulsion system:

[0073] The pretreated oil-soluble quantum dots obtained in step 1 were thoroughly mixed with 100 μL of a 1% sodium dodecyl sulfate solution using dichloromethane as a solvent, and the mixture was shaken for 3 minutes to obtain a first liquid system 2;

[0074] Then, the first liquid system 2, 20 μL of a 1% polyvinyl pyrrolidone (PVP) aqueous solution, and 10 μL of a 1% polyvinyl alcohol (PVA) aqueous solution were mixed and shaken for 10 minutes to mix evenly, thereby obtaining a second liquid system 2.

[0075] 3. Removal of solvent and excess ligand:

[0076] Add 300 μL of water to the second liquid system 2 obtained in step 2, shake for 10 minutes to mix, and ultrasonicate to remove the dichloromethane solvent; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate, and disperse the precipitate in 700 μL of ultrapure water; then add 1 mL of anhydrous ethanol, centrifuge at 4000 rpm for 3 minutes, collect the precipitate 1, and obtain water-soluble quantum dots 3. Dissolve the water-soluble quantum dots 3 in 500 μL of ultrapure water for later use.

[0077] Example 4 Preparation of Water-Soluble Quantum Dot-Conjugated Drug Antibodies

[0078] In this embodiment, only morphine antibodies are selected to couple with water-soluble quantum dots 1, which does not mean that water-soluble quantum dots 1 can only be coupled with morphine antibodies. Morphine antibodies can be conventional drug antibodies, such as methamphetamine antibodies, ketamine antibodies, etc.

[0079] The water-soluble quantum dots 1 prepared in Example 1 were used to prepare water-soluble quantum dots 1 coupled with morphine antibodies. The specific steps are as follows:

[0080] 10 μL of morphine antibody was dissolved in 50 μL of ultrapure water to obtain a morphine antibody solution; the water-soluble quantum dots 1 prepared in Example 1 (water-soluble quantum dots 1 dissolved in 500 μL of ultrapure water for standby use) and the morphine antibody were placed in a 1.5 mL EP tube and shaken for 20 minutes to mix evenly. Then, 100 μL of a 10% mass concentration of glycine aqueous solution (blocking agent) was added and shaken for 10 minutes to fully react. Then, 1 mL of anhydrous ethanol was added to precipitate the quantum dots, and the mixture was centrifuged at 4000 rpm for 3 minutes. The precipitate was collected as the water-soluble quantum dots 1 coupled with the morphine antibody, and dispersed in 500 μL of PBS buffer for standby use.

[0081] Example 5 Preparation of a test strip for detecting drugs in hair

[0082] In this embodiment, how chitosan and surfactant are sprayed on the glass fiber mat, the composition ratio between the various substances, how the morphine antigen and secondary antibody are coated on the NC membrane, the assembly method of the immune test strip, and how the immunochromatographic test strip is transferred into the cartridge are all conventional processes in the field and are not the innovation of the present invention. Therefore, they are not described in detail in the specific process of the embodiment, and conventional methods and dosages in the field can be used.

[0083] The water-soluble quantum dots 1 coupled with morphine antibodies prepared in Example 4 were used to prepare a test strip for detecting hair drugs. The specific preparation process is as follows:

[0084] 1. Preparation method

[0085] The water-soluble quantum dots 1 coupled with morphine antibodies prepared in Example 4, chitosan and Tween-20 were uniformly mixed to obtain a mixed solution, and the mixed solution was sprayed on a glass fiber mat to obtain a conjugate pad with water-soluble quantum dots 1 coupled with morphine antibodies.

[0086] A test line (T line) and a quality control line (C line) are set on the NC membrane, wherein the test line (T line) is coated with morphine antigen, and the quality control line is coated with goat anti-mouse secondary antibody. The NC membrane with the T line and C line coated is dried to obtain an immunochromatographic reaction membrane.

[0087] The sample pad, the binding pad with water-soluble quantum dots 1 coupled with morphine antibodies, the immunochromatographic reaction membrane and the absorbent pad are sequentially pasted on the PVC base plate, and then cut into test strips with a width of 4 mm to obtain a test paper card for detecting hair drugs. The test paper strip for detecting hair drugs is placed in the card shell to obtain the corresponding test paper strip.

[0088] The absorbent pad is absorbent paper, and the structural diagram of the test paper card for detecting hair drugs is as follows: Figure 2 shown.

[0089] 2. Usage

[0090] A series of standard test samples of morphine samples were prepared and added to the sample pad of the test strip for each concentration. After waiting for 5 minutes, the T-line and C-line fluorescence signal values ​​of the immunochromatographic reaction membrane of the test strip corresponding to each concentration were detected using a spectrometer. The ratio of the T-line fluorescence signal value to the C-line fluorescence signal value was calculated and recorded as T / C.

[0091] Draw a standard curve with the concentration of the standard test product as the horizontal axis and T / C as the vertical axis.

[0092] Add the sample to be tested to the sample pad of the test strip. After waiting for 5 minutes, use a spectrometer to detect the fluorescence signal values ​​of the T line and C line of the test strip corresponding to the sample to be tested, and calculate T / C. Combined with the standard curve, the concentration of the sample to be tested can be calculated.

[0093] Example 6 Immunochromatographic Test Strip Detection Experiment

[0094] Taking the test strip prepared in Example 5 as an example, the morphine content in hair samples was detected, wherein the hair samples included hair samples with morphine content of 0.1 ng / mL, 0.5 ng / mL, 1 ng / mL, 2 ng / mL, and 5 ng / mL.

[0095] 1. Experimental methods

[0096] Taking a hair sample with a morphine content of 0.1 ng / mL as an example, 10 g of the hair sample was weighed, and the hair sample, microbeads, and a hair grinding aid (containing 0.2 M TRIS-HCl and 0.85% NaCl) were ground for 3 to 5 minutes to obtain a hair extract.

[0097] 50-100 μL of hair extract was added dropwise to the sample pad of the test strip prepared in Example 5, and then the fluorescence signal values ​​of the T line and C line on the immunochromatographic reaction membrane of the test strip were detected using a spectrometer.

[0098] Hair samples with other morphine contents were tested using the same method and the test results were recorded.

[0099] 2. Experimental results

[0100] The test results of the test strips are shown in Table 1 and Figure 3 shown.

[0101] Table 1 Test results of immunochromatographic test strip 1

[0102]

[0103] Figure 3 The T / C curves of hair samples with different morphine concentrations in this example are shown in Figure 2, where the curve fitting goodness R 2 The value of is 0.9927. The better the regression line fits the observed value, the closer the detection value is to the actual value. The results show that within the concentration range of 0.1ng / mL to 5ng / mL, the T / C value of the test strip has a good correlation with the morphine concentration in the hair sample, and the detection sensitivity of the test strip for morphine reaches 0.1ng / mL, which is far lower than the detection threshold of multiple metabolite content in hair samples of drug-related personnel (2ng / mL) stipulated by the Ministry of Public Security.

[0104] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that other variations or modifications may be made based on the above descriptions and concepts. It is not necessary and impossible to provide an exhaustive list of all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing water-soluble quantum dots, characterized in that: The following steps are involved: S1. The oil-soluble quantum dots are mixed with the dispersion and mixed thoroughly to obtain a first liquid system; The solute of the dispersion includes a surfactant, and the solvent is an oily solvent; The surfactant is cetyltrimethylammonium bromide, sodium lauryl sulfate and / or sodium lauryl sulfonate; S2. The first liquid system obtained in step S1 is mixed with a water-soluble polymer ligand solution to obtain a second liquid system; The water-soluble polymer ligand solution is a polyvinyl alcohol aqueous solution and a polyvinyl pyrrolidone aqueous solution; S3. Removing the oily solvent and the excess water-soluble polymer ligand solution from the dispersion in the second liquid system obtained in step S2 to obtain water-soluble quantum dots.

2. The preparation method according to claim 1, characterized in that The oil-soluble quantum dots in step S1 are dispersed and dissolved in hexane, toluene and / or chloroform and then washed.

3. The preparation method according to claim 1, characterized in that The dispersion in step S1 is a solution of hexadecyltrimethylammonium bromide, sodium dodecyl sulfate and / or sodium dodecyl sulfonate using dichloromethane as a solvent.

4. The preparation method according to claim 3, characterized in that The mass concentration of the dispersion is 0.05% to 1%.

5. The preparation method according to claim 1, characterized in that The mass concentration of the polyvinyl alcohol aqueous solution in step S2 is 0.1% to 1%; the mass concentration of the polyvinyl pyrrolidone aqueous solution is 0.2% to 1%.

6. The preparation method according to claim 5, characterized in that The volume ratio of the polyvinyl alcohol aqueous solution, the polyvinyl pyrrolidone aqueous solution and the dispersion in step S1 is 10-100:20-100:

100.

7. Water-soluble quantum dots prepared by the preparation method according to any one of claims 1 to 6.

8. A reagent for detecting drugs, characterized in that: The reagent is the water-soluble quantum dots according to claim 7 coupled with drug antibodies; The drug antibodies are morphine antibodies, methamphetamine antibodies and / or ketamine antibodies.

9. An immunochromatographic test strip, characterized in that: The base plate includes a sample pad, a conjugate pad, an immunochromatographic reaction membrane and a water-absorbing pad which are sequentially arranged on the base plate; The conjugate pad is coated with the reagent according to claim 8.

10. Use of the water-soluble quantum dots according to claim 7, the reagent according to claim 8 and / or the immunochromatographic test strip according to claim 9 in hair drug detection.

Images