CN211453649U - Immunochromatography test strip based on quantum dot fluorescent microspheres - Google Patents

Abstract

The utility model discloses an immunochromatography test strip based on quantum dot fluorescent microspheres, which comprises a bottom plate, a sample pad, a nitrocellulose membrane and a water absorption pad, wherein the sample pad is lapped on the upper surface of one end of the nitrocellulose membrane, the water absorption pad is connected on the upper surface of the other end of the nitrocellulose membrane, and a detection line and a quality control line which are parallel to the end surface of the bottom plate are coated on the exposed nitrocellulose membrane between the end part of the sample pad and the end part of the water absorption pad; 1mg/mL cyproheptadine hydrochloride competitive antigen is fixed on the surface of the detection line; goat anti-mouse IgG with the concentration of 0.3mg/mL is fixed on the surface of the quality control line; the test strip can realize rapid qualitative and quantitative detection of cyproheptadine hydrochloride by a fluorescent card reader, and the minimum detection limit reaches 0.096 ng/mL; the test strip provided by the utility model has the characteristics of easy operation, fast detection speed, high sensitivity and the like, and can be used for the residual determination of cyproheptadine hydrochloride in pig urine.

Description

Immunochromatographic test strips based on quantum dot fluorescent microspheres

technical field

The utility model belongs to the technical field of immunoassay, in particular to a quantum dot fluorescent microsphere immunochromatographic test strip for rapidly detecting cyproheptadine hydrochloride.

Background technique

Cyproheptadine hydrochloride, as a medical drug, is used for the treatment of various allergic diseases such as skin itching, contact dermatitis, allergic rhinitis, etc. It also inhibits the satiety center of the hypothalamus to stimulate appetite, increase body weight, and promote growth. . Cyproheptadine hydrochloride is also illegally added to animal feed, which can produce a similar effect to "clenbuterol" Clenbuterol hydrochloride, promote the growth of livestock and poultry and improve the lean meat rate, so it is called a new type of "clenbuterol". . Human long-term consumption of meat food with cyproheptadine hydrochloride residues can seriously damage human health, resulting in fatigue, dizziness, drowsiness, respiratory depression and other adverse symptoms, severe cases can lead to coma or even death, especially children and the elderly are the most sensitive. Therefore, the Ministry of Agriculture of China issued Announcement No. 1519 in 2010, prohibiting the use or addition of cyproheptadine hydrochloride in feed and animal drinking water.

At present, the detection methods of cyproheptadine hydrochloride are mainly instrument detection, such as high performance liquid chromatography and liquid chromatography-mass spectrometry detection methods. The detection of these detection methods takes a lot of time, the required detection equipment is expensive, and the operation of specialized laboratory personnel is required, which is not conducive to the rapid detection of a large number of samples. Enzyme-linked immunoassay (ELISA) has the advantages of high sensitivity, good recovery and strong specificity, and can achieve rapid on-site qualitative and semi-quantitative analysis, and has been widely used in drug residue detection, but this method still requires operators professional training. Immunochromatographic test strips based on the ELISA principle do not require professionally trained operators, are simpler and faster, have lower costs, are more sensitive, and do not require complex instruments and equipment. It has been widely used in security detection and other fields.

Quantum dot fluorescent microsphere immunochromatography is an immunochromatographic technique established with quantum dot fluorescent microspheres as markers. Quantum dots have good biocompatibility and can be specifically coupled with biomolecules such as nucleic acids, antibodies and DNA after chemical modification on their surfaces. Quantum dot fluorescent microspheres are a kind of fluorescent marker formed by embedding quantum dot fluorescent dyes or by adsorption on a polymer carrier, which can effectively improve the sensitivity of the reaction, and is regarded as a kind of fluorescent label in the field of immunochromatographic detection technology. As the most promising fluorescent marker, the process of coupling antibody to quantum dot fluorescent microspheres is a key part of the whole method, and the effect of coupling ultimately affects the improvement of sensitivity. At present, quantum dot technology is mainly used to detect protein biomarkers and other small molecule compounds. The detection of cyproheptadine hydrochloride by quantum dot fluorescent microsphere immunochromatography has not been reported yet.

Utility model content

The utility model provides an immunochromatographic test strip based on quantum dot fluorescent microspheres, which can realize simple, fast and highly sensitive quantitative detection of cyproheptadine hydrochloride. The utility model is realized through the following technical solutions:

First, the utility model provides an immunochromatographic test strip based on quantum dot fluorescent microspheres, comprising a bottom plate, a sample pad, a nitrocellulose membrane and a water-absorbing pad, and the sample pad is overlapped on the upper surface of one end of the nitrocellulose membrane , the absorbent pad is connected to the upper surface of the other end of the nitrocellulose membrane, and the exposed nitrocellulose membrane between the end of the sample pad and the end of the absorbent pad is coated with a detection line and a quality control line parallel to the end face of the bottom plate;

1 mg/mL cyproheptadine hydrochloride competition antigen is fixed on the surface of the detection line;

The surface of the quality control line is immobilized with goat anti-mouse IgG at a concentration of 0.3 mg/mL;

In the specific implementation, before the sample pad is assembled, it is preferably soaked in a buffer solution for 24 hours, and the buffer solution components are: in mass percentage, 2% BSA, 2.5% sucrose, 0.02% sodium azide NaN ₃ , and PBS is used to make up the remainder. amount, pH 7.4;

The detection sensitivity of the test strip for cyproheptadine hydrochloride reached 0.096 ng/mL.

Further, in the immunochromatographic test strip based on quantum dot fluorescent microspheres provided by the present invention, the interval between the detection line and the quality control line is 3-8 mm.

Secondly, the present invention also provides the application of the above-mentioned immunochromatographic test strip based on quantum dot fluorescent microspheres in the detection of cyproheptadine hydrochloride. The specific detection method is as follows:

(1) The anti-cyproheptadine hydrochloride monoclonal antibody-quantum dot fluorescent probe was mixed with the cyproheptadine hydrochloride standard and incubated for 1 min, and then dropped on the sample pad. Color development of the quality control line, that is, record the fluorescence intensity of the test strip detection line (T line) and the quality control line (C line) with a fluorescence reader, and establish a linear relationship between the inhibition rate and the concentration of the cyproheptadine hydrochloride standard through calculation. Draw the standard curve: y=95.81-99.22/(1+(x/0.9) ^0.83 ); if the quality control line (C line) of the test strip does not develop color under UV light irradiation, the test strip is judged to be invalid; The concentration of the standard cyproheptadine hydrochloride is 0-50 ng/mL (Fig. 5), preferably the concentration of the standard cyproheptadine hydrochloride is 0, 0.78, 1.56, 3.125, 6.25, 12.5, 25, and 50 ng/mL. mL (Figure 4).

(2) Put the sample to be tested in a centrifuge tube, centrifuge at 3000 g for 10 min; aspirate the supernatant and mix it with the diluent in a volume ratio of 1:4 to obtain a sample diluent, and repeat step (1) for detection: Under the illumination of the lamp, the quality control line of the test strip develops color, and the content of cyproheptadine hydrochloride can be judged according to the degree of color development of the test line, and the fluorescence intensity of the test line and the quality control line of the test strip is recorded by a fluorescence reader. Calculate the inhibition rate by fluorescence numerical value, and substitute it into the curve equation of step (1) to obtain the content of cyproheptadine hydrochloride in the sample; if the quality control line does not develop color under UV irradiation, the test strip is judged to be invalid. Further, in the above detection method, the anti-cyproheptadine hydrochloride monoclonal antibody-quantum dot fluorescent microsphere probe is obtained by the following method:

Dissolve 0.12 mg of quantum dot fluorescent microspheres in pH 6.0, 2.7 mL of 0.01 mol/L phosphate buffer, add 1 μg of EDC for activation, and then add 150 μg of cyproheptadine hydrochloride. After mixing, magnetically stir for 30 minutes. min, centrifuge at 13,500 rpm for 15 min, remove the supernatant, reconstitute the centrifuged pellet with 600 μL of reconstituted solution, and store at 4°C.

Compound solution formula: Calculated by mass percentage, 5% sucrose, 2% fructose, 1% PEG 20000, 1% BSA, 0.4% Tween-20, and deionized water to make up the balance.

The method of anti-cyproheptadine hydrochloride monoclonal antibody-quantum dot fluorescent probe in this step can also be found in the literature: "RenM , Xu H , Huang X , et al. Immunochromatographic assay for ultrasensitive detection of aflatoxin B ₁ in maize by highly luminescent quantum dot beads.[J]. Acs Applied Materials & Interfaces, 2014, 6(16):14215-14222.”.

In the present invention, the quantum dot fluorescent microspheres are preferably obtained by doping CdSe/ZnS quantum dots, with a diameter of 247 nm ± 13 nm. The quantum dot fluorescent microspheres are the prior art and can be purchased in the market or prepared by yourself. For the preparation method, please refer to the literature. : "Ren M , Xu H , Huang X , et al. Immunochromatographic assay for ultrasensitive detection of aflatoxin B ₁ in maize by highly luminescentquantum dot beads. [J]. Acs Applied Materials & Interfaces, 2014, 6(16):14215-14222 .".

Compared with the existing detection method, the test strip provided by the utility model and the detection beneficial effects thereof:

(1) A kind of cyproheptadine hydrochloride immunochromatographic test strip based on quantum dot fluorescent microspheres provided by the present utility model, compared with traditional analysis technology, can realize more rapid, convenient and sensitive detection of cyproheptadine hydrochloride, using A portable fluorescence card reader can perform on-site real-time quantitative detection. The test strip can be used to detect cyproheptadine hydrochloride in various sample sources, such as pig urine, animal feed, pork tissue, etc.

(2) The cyproheptadine hydrochloride fluorescent immunochromatography test strip based on quantum dot fluorescent microspheres provided by the present utility model greatly improves the detection sensitivity of the method due to the introduction of quantum dot fluorescent probes. Limited to ELISA methods that are better than the same antibody.

(3) The detection method of the cyproheptadine hydrochloride immunochromatographic test strip based on the quantum dot fluorescent microspheres of the present invention can realize the quantitative detection of cyproheptadine hydrochloride in the sample.

Description of drawings

Fig. 1 is the standard inhibition curve of monoclonal antibody against cyproheptadine hydrochloride detected by indirect competitive ELISA method.

Fig. 2 is the principle schematic diagram of cyproheptadine hydrochloride immunochromatographic test strip based on quantum dot fluorescent microspheres of the present utility model

3 is a schematic diagram of the interpretation of the results of rapid detection of cyproheptadine hydrochloride according to the present invention.

Figure 4 is a graph of the sensitivity experiment for detecting cyproheptadine hydrochloride at different concentrations.

Fig. 5 is the detection standard curve of cyproheptadine hydrochloride by the immunochromatographic test strip of the present invention.

Detailed ways

Example 1 Preparation of Cyproheptadine Hydrochloride Monoclonal Antibody

1. Synthesis of immunogen (CYP-BSA) and competing antigen (CYP-OVA)

1.1 Dissolve 0.05 mmol of cyproheptadine hydrochloride hapten in 1 mL of dimethylformamide (DMF), and then add N-hydroxysuccinimide (NHS) (0.06 mmol) and N,N-dicyclohexyl carbon in sequence Diimine (DCC) (0.06 mmol) was stirred at room temperature and protected from light and left overnight.

1.2 On the second day, the mixture left overnight was centrifuged at 10,000 g for 10 min, and the supernatant was selected for use.

1.3 Dissolve BSA (0.15×10 ^-3 mmol) and OVA (0.15×10 ^-3 mmol) in 5 mL of PBS respectively to prepare a protein solution; slowly add the solution obtained in step 1.2 dropwise to the protein solution and place it in the Stir at room temperature for 4 hours;

1.4 After the reaction was completed, the resultant was dialyzed in PBS at 4 ^oC for three days, and the dialysate was replaced 3-4 times a day. The products obtained after dialysis were the immunogen (CYP-BSA) and the competing antigen (CYP-OVA). , and stored at -20 ^o C.

In this step, the cyproheptadine hydrochloride hapten can be purchased commercially or prepared by itself, and the preparation method is a conventional technique in the field, such as the literature "Yang Qianru. Research on the new "clenbuterol" cyproheptadine hydrochloride immunodetection technology [D]. "The disclosed preparation method.

2. Identification of Cyproheptadine Hydrochloride Artificial Antigen

The synthetic cyproheptadine hydrochloride immunization antigen, competition antigen and carrier protein were scanned by ultraviolet 200-400 nm respectively, and their binding ratios were calculated by comparing the absorbance values of the three at the same wavelength.

Compared with the carrier protein, the UV spectra of the immunogen and the competing antigen shifted the maximum absorption wavelength, indicating that the hapten had been successfully coupled with the carrier protein to obtain the cyproheptadine hydrochloride artificial antigen. After calculation, the binding ratio of the obtained artificial antigen cyproheptadine hydrochloride hapten molecule and BSA molecule is 20:1, and the binding ratio of cyproheptadine hydrochloride hapten molecule and OVA molecule is 18:1, which proves that there is a good coupling. Effect.

3. Preparation of Cyproheptadine hydrochloride

Select 6-8-week-old Balb/c female mice and immunize them four times. The dose of each immunogen (CYP-BSA obtained in step 1.4) is 100 μg/mouse, and the interval between each immunization is 3 weeks. For the primary immunization, the immunizing antigen and Freund's complete adjuvant were mixed in equal volumes and injected intraperitoneally. Three days before fusion, 150 μg of immunogen was injected into each animal for booster immunization. On the 6th day after immunization, blood was collected from the tail, and the titer was determined by ELISA. The immunized mouse spleen cells with the highest titer were mixed with mouse myeloma cells SP2/0 cells, and the cells were fused with 50% PEG as a fusion agent. When the cells grew to 1/4 of the culture well area, the step-by-step screening method Screening of hybridoma cells. Indirect ELISA method was used to identify the properties of antibodies in the cell supernatant. If the OD ₄₅₀ nm value after blocking by cyproheptadine hydrochloride dropped to less than 50% of the control well, it was positive, and it was positive after 2-3 tests. Wells were immediately subcloned by limiting dilution. The hybridoma cells after 2-3 times of subcloning were expanded and cultured, and the supernatant was collected to determine the titer by indirect ELISA, and then cryopreserved; 8-10-week-old Balb/c mice were injected intraperitoneally with 0.5 mL of liquid paraffin per mouse 7-10 days later, intraperitoneal injection of 1-2 × 10 ⁶ hybridoma cells per mouse was performed, and ascites was extracted from mice 7-10 days later, and the supernatant was collected by centrifugation.

The preparation methods of steps 2 and 3 can also be found in the literature "Yang Qianru. Research on the new "clenbuterol" cyproheptadine hydrochloride immunodetection technology [D]" and "Yan Liting. The preparation of general organophosphorus and camptothecin monoclonal antibodies and Immunodetection Technology Research [D]." The method disclosed.

4. Purification of ascites

4.1 Mix 5 mL of ascites with an equal volume of PBS, add 5 mL of saturated ammonium sulfate solution to it, add it dropwise while stirring, and continue stirring at room temperature for 30 min, and place it in a 4°C refrigerator to cool overnight to allow the immune system. The globulin was well precipitated.

4.2 Centrifuge the fully precipitated mixture, 4 ^o C, 10000 g/min, 20 min, dissolve the precipitate with 5 mL of PBS, add 3 mL of saturated ammonium sulfate solution dropwise to it while stirring, and continue to stir for 30 min , refrigerate at 4 ^o C overnight.

4.3 Repeat step 4.2 twice, dissolve the precipitate after the last centrifugation with 5 mL PBS, put it into a dialysis bag, dialyze it with PBS for 3 days, change the medium 3-4 times a day, and fully remove the salt.

4.4 Centrifuge the dialysis product, 4 ^o C, 5000 g/min, 50 min. The supernatant is the crudely extracted cyproheptadine hydrochloride, which is stored in aliquots at -20 ^o C for subsequent use.

The detection sensitivity of monoclonal antibody was identified by indirect competitive ELISA. For the detection method, please refer to the method disclosed in the literature "Yan Liting. Preparation of universal organophosphorus and camptothecin monoclonal antibodies and research on immunodetection technology [D].". The detection results are shown in Figure 1, and the formula for drawing a standard curve at the same time is: y=90.6-90.23/(1+(x/6.52) ^0.95 ), where x represents the concentration of the standard cyproheptadine hydrochloride, and y represents the cyproheptadine hydrochloride Inhibition rate of monoclonal antibody against pyridine standard. As shown in Figure 1, the concentration of cyproheptadine hydrochloride standard (IC ₅₀ ) is 8.05 ng/mL when the inhibition rate of monoclonal antibody is 50%, and the lowest detection line (IC ₁₀ ) is 0.70 ng/mL , the detection range (IC ₂₀ -IC ₈₀ ) is 1.69-54.46 ng/mL.

Example 2 Preparation of anti-cyproheptadine hydrochloride monoclonal antibody-quantum dot fluorescent probe

Dissolve 0.12 mg of quantum dot fluorescent microspheres in pH 6.0, 2.7 mL of 0.01 mol/L phosphate buffer, add 1 μg of EDC for activation, and then add 150 μg of cyproheptadine hydrochloride. After mixing, magnetically stir for 30 minutes. min, centrifuge at 13,500 rpm for 15 min, remove the supernatant, reconstitute the centrifuged pellet with 600 μL of reconstituted solution, and store at 4°C.

Compound solution formula: Calculated by mass percentage, 5% sucrose, 2% fructose, 1% PEG 20000, 1% BSA, 0.4% Tween-20, and deionized water to make up the balance.

The preparation method of the above quantum dot fluorescent microspheres can also be found in the literature "Duan H , Chen X , Xu W , etal. Quantum-DoT submicrobead-based immunochromatographic assay for quantitative and sensitive detection of zearalenone [J]. Talanta, 2015, 132:126 -131.". The disclosed method is prepared; the above-mentioned anti-cyproheptadine hydrochloride monoclonal antibody-quantum dot fluorescent probe method can also refer to the document "Ren M, Xu H, Huang X, et al. Immunochromatographic assay for ultrasensitive detection of aflatoxin B ₁ in maize by highly luminescentquantum dot beads.[J]. Acs Applied Materials & Interfaces, 2014, 6(16):14215-14222.”

Example 3 Preparation of test strips

As shown in Figure 2A, an immunochromatographic test strip based on quantum dot fluorescent microspheres includes a PVC bottom plate, a sample pad 1, a nitrocellulose membrane 4 and a water-absorbing pad 5, and the sample pad 1 is overlapped on the nitrocellulose membrane The upper surface of one end of 4 (the adjacent pads overlap by 2mm), the absorbent pad 5 is connected to the upper surface of the other end of the nitrocellulose membrane 4 (the adjacent pads overlap by 2 mm), the end of the sample pad 1 and the end of the absorbent pad 5 The exposed nitrocellulose membrane 4 is coated with a detection line 2 (T line) and a quality control line 3 (C line) parallel to the end face of the bottom plate.

As shown in Figure 2B, the assembled test strip is cut into 4 mm wide and 60 mm long strips using a strip cutter, and placed in a white long strip-shaped flat detection card. The surface of the detection shell 6 is provided with The sample addition hole 7 and the inspection window 8 are suitable for injecting the sample to be detected and the fluorescent probe on the test strip from the sample addition hole 7; the inspection window 8 is convenient for the operator to observe the experimental results.

The surface of the detection line is immobilized with 1 mg/mL cyproheptadine hydrochloride competition antigen (CYP-OVA prepared in step 1.4 of Example 1);

The surface of the quality control line is immobilized with goat anti-mouse IgG at a concentration of 0.3 mg/mL;

In this embodiment, the sample pad should be soaked in buffer solution for 1 hour before assembly, and then assembled after drying at room temperature; the soaking step can reduce sample differences, improve experimental sensitivity, avoid the trouble of complex identifiers and tracking buffers, and make detection in one step. Finish.

The components of the buffer solution are: 2% BSA, 2.5% sucrose, 0.02% sodium azide NaN3 in mass percentage, the balance is made up with PBS, pH 7.4.

The above-mentioned goat anti-mouse IgG can be purchased commercially, or refer to the literature "Liu B, Gong H, Wang Y, et al. Agold immunochromatographic assay for simultaneous detection of parathion and triazophos in agricultural products [J]. ANALYTICAL METHODS, 2018, 10.".

Example 4 Quantum dot fluorescent microsphere test strip detection application

(1) Result judgment

Take 1 μL of the quantum dot fluorescent probe prepared in Example 2 and mix it with PBS buffer containing 5% methanol and buffer containing cyproheptadine hydrochloride with different concentrations respectively. After incubation at room temperature for 1 min, add test strips for sample loading. After 15 min of reaction, it was detected with a test strip reader. The experimental group without cyproheptadine hydrochloride standard was used as the negative control group. After entering the test strip into the reader (dry fluorescence immunoassay analyzer, model: FIC-S2011-L44, manufacturer: Suzhou Hemai Precision Instrument Co., Ltd.), after excitation by optical components, the quantum dots at the T and C lines of the test strip are The fluorescent microspheres emit fluorescent signals, and the instrument converts the fluorescent signals into digital signals and displays them on the display of the reader. After 15 minutes, if the C line develops color and the color intensity of the T line is comparable to that of the T line in the negative control group (as shown in Figure 3B), the result is a negative result; if both the T and C lines develop color, and the color intensity of the T line is higher than that of the negative control If the T line in the group is small (as shown in Figure 3C), or if the C line develops color and the T line does not develop color (as shown in Figure 3D), it is a positive result; if the C line does not develop color, the test strip is judged to be invalid, (such as Figure 3 E, F), wherein Figure 3A is a negative control. As shown in Figure 4, from left to right, the concentration of the standard is 0, 0.78, 1.56, 3.125, 6.25, 12.5, 25, 50 ng/mL, and the T-line brightness gradually dims until it is invisible to the naked eye, which is in line with the expected results of the experiment , the qualitative detection of cyproheptadine residues can be initially realized.

(2) Determination of standard curve

Cyproheptadine hydrochloride standard was diluted 2-fold in PBS buffer containing 5% methanol by volume, the concentrations were: 0.048828125, 0.09765625, 0.1953125, 0.390625, 0.78125, 1.5625, 3.125, 6.25, 12.5, 25, 50 each The concentration was measured in five parallel repetitions. After 15 minutes, the fluorescence intensity of the _T and _C lines of the test strip was recorded with a fluorescence reader. The FIT/FIC ratio of the standard solution with a concentration of 0 was set to be B ₀ , and the FIT of other standard concentrations was set as B 0 _. The ratio of /FI _C is B, take (B ₀ -B)/B ₀ ×100 (%) as the ordinate and the concentration of cyproheptadine hydrochloride as the abscissa to draw the graph, and draw the test strip competition inhibition curve, and the obtained standard curve is as follows shown in Figure 5. Inhibition curve formula: y=95.81-99.22/(1+(x/0.9) ^0.83 ), calculated according to the formula: IC ₅₀ is 1.09 ng/mL, the lowest detection line is 0.096 ng/mL, and the detection range is 0.22-6.68 ng/mL.

(3) Sample processing

Take 2 mL of pig urine sample into a polystyrene centrifuge tube and centrifuge at 3000 g for 10 min; aspirate the supernatant and mix it with the diluent at a volume of 1:4; take an appropriate amount of the mixture (sample diluent) for detection.

The diluent was a PBS buffer containing 5% methanol by volume.

(4) Detection of samples

Add cyproheptadine hydrochloride standard to the urine sample without cyproheptadine hydrochloride, so that the final concentration of the standard in the sample is 1, 5, and 20 mg/L; Detection, each experiment was repeated 5 times, and the coefficient of variation and recovery rate of addition were calculated respectively. The results are shown in Table 1, respectively.

Table 1 The experimental results of standard addition and recovery

Additive concentration (mg/L) Recovery rate Coefficient of variation 1 94% 3.5% 5 81% 1.5% 20 104% 7%

The results showed that the average additive recovery of pig urine samples was 94-104%, and the coefficient of variation was 1.5-7%. This test result shows that the method can accurately detect the content of cyproheptadine hydrochloride in pig urine.

(4) Cross-reaction rate test

Drugs similar in structure or function to cyproheptadine, such as fretadine, ketotifen fumarate, and clonidine hydrochloride, were selected for cross-reaction test, and their IC ₅₀ was obtained through the standard curve of each drug. The IC50 _{Cyproheptadine} HCl/ _IC50 Analogue was used to calculate the cross-reactivity of the test strips to other Cyproheptadine analogs. The smaller the cross-reaction rate with other drugs, the better the detection specificity of the quantum dot fluorescent microsphere immunochromatographic test strip for cyproheptadine hydrochloride. As a result, the quantum dot fluorescent microsphere immunochromatographic test strip has a cross-reaction rate＜1% to fretadine, ketotifen, and clonidine hydrochloride, indicating that the method has good specificity, and the utility model can be used to detect pig urine residual cyproheptadine hydrochloride.

Claims (2)

1. an immunochromatographic test strip based on quantum dot fluorescent microspheres, comprising a bottom plate, a sample pad, a nitrocellulose membrane and a water-absorbing pad, it is characterized in that, the sample pad is overlapped on one end of the nitrocellulose membrane Surface, the water-absorbing pad is connected to the upper surface of the other end of the nitrocellulose membrane, and the exposed nitrocellulose membrane between the end of the sample pad and the end of the water-absorbing pad is coated with a detection line and a quality control line parallel to the end face of the bottom plate; Cyproheptadine hydrochloride competition antigen is immobilized on the surface of the detection line; goat anti-mouse IgG is immobilized on the surface of the quality control line. 2. The immunochromatographic test strip based on quantum dot fluorescent microspheres according to claim 1, wherein the interval between the detection line and the quality control line is 3-8 mm.

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