Method for quantum dot mark indirect competition fluoroimmunoassay detection for becort

[0028] (1) Use denatured bovine serum albumin (dBSA) to wrap green QD590 labeled anti-betamethasone polyclonal antibody

[0029] (1) BSA degeneration:

[0030] Dissolve 16.5mg BSA in 10mL double-distilled water, add 0.42mg NaBH under stirring 4 ,Reaction at room temperature for 1h, heating at 60-80℃ for 20min to decompose excess NaBH 4 , BSA is denatured, the disulfide bond opens into -SH, and the final concentration of the dBSA aqueous solution is 5×10 -5 M.

[0031] (2) Denatured BSA wrapped quantum dots (dBSA-QDs):

[0032] The dBSA and quantum dots chromium dysprosium (CdTe) are mixed at a certain molar ratio (1:1), heated in a water bath at 60-80°C for 15 minutes, and kept at room temperature for two days to complete the package.

[0033] (3) Denatured BSA coated quantum dot conjugated antibody

[0034] Mix 5 μL 1-ethyl-(3-dimethylaminopropyl) carbodiimide EDC (0.056M) and 5 μL thio N-hydroxysuccinimide sulfo-NHS (0.1M) for 10 seconds, then add to 25μL dBSA-QDs(2×10 -5 In M),...

[0041] Example 2 Addition and recovery experiment

[0042] (1) Extraction and purification of the sample: Add 10mL of acetonitrile / water (7:3) mixed solution to 2g of chicken meat sample, vortex for 1min, ultrasonic for 30min, centrifuge at 2000×g for 10min, draw 2.5mL of supernatant liquid and clean Add 4 mL of n-hexane and 1 mL of dichloromethane to the glass tube for degreasing, vortex for 1 min to separate the three phases, draw 1 mL of the intermediate phase (corresponding to 0.2g sample) in a clean test tube; 50℃, slow N 2 Flow dry, and dissolve the residue with 0.2 mL of standard diluent (phosphate buffered saline PBST containing Tween-20 containing 10% methanol) and use it as a sample for analysis.

[0043] (2) Add betamethasone standard solution to 2g blank chicken sample to make the concentration of 1ng / g, 5ng / g, 10ng / g, 20ng / g, and prepare five samples for each concentration. The processing method is analyzed after extraction. The results are shown in Table 1. It can be...