目的:构建挂于Nafion/纳米金(AuNPs)包被牛血清蛋白-氯霉素载体抗原(CAP—BSA)丝网印刷碳电极(SPCEs)的一次性安培免疫传感器(SPCEsJNafion/AuNPs/CAP—BSA),并用于牛奶中氯霉素(CAP)含量测定。方法:采用循环伏安法(CV)和示差脉冲伏安法(DPV)研究CAP在该免疫传感器上的电化学行为,并通过竞争性免疫分析法测定CAP含量。结果:该免疫传感器在含1mmol·L^-1铁氰化钾和100μg·L^-1CAP抗体(anti—CAP)的25μLpH=6.0磷酸盐缓冲溶液(PBS)中加入不同浓度的CAP,并在25℃下温育6min,DPV还原峰电流上升百分比(Cl,%)与CAP浓度分别在0.2~10.0μg·L^-1(R2=0.9946)和10.0~100μg·L^-1(R2=0.9647)范围内呈线性关系,检测限为0.11μg·L^-1(3σ法)。应用于牛奶中CAP检测并与传统的高效液相色谱法(HPLC)比较,结果一致,其添加回收率在88%~102%之间。结论:该免疫传感器灵敏快速(10min)、制备容易(碳浆印刷)、样品用量少(2μL)、可抛弃,有单用于食品中痕量CAP快速筛测。
Objective: A disposable amperometric immunosensor was fabricated by Nation membrance and gold nanoparticles coated chloramphenicol- bovine serum albumin( CAP- BSA) modified on screen- printed carbon electrodes(SPCEs ] Nafion/AuNPs/CAP- BSA)whieh was employed to determine CAP in milk. Method:The electrochemical behavior of the immunosensor was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The content of CAP was determined with competitive immunoassay. Result: When different concentration of CAP were added in 25 μL pH = 6.0 phosphate buffer solution (PBS) containing 1 mmol ·L^-1 K3Fe (CN) 6and 100 μg · L^-1 anti -CAP ,the percentage of cathodic peak DPV current increase ratio (Cl ,% ) was proportional to the concentration of CAP over the range of 0.2 - 10.0 μg · L^-1 (R2 =0. 9946) and 10.0 - 100 μg · L^-1(R2 = 0. 9647) after incubation for 6 rain at 25 ℃. The detection limit was 0. 11 μg · L^-1 (on a 30- basis). The immunosensor was employed to determine CAP in real milk samples and the recovery rates exhibited a range of 88% - 102%. The results were consistent to the tradition HPLC method. Conclusion:The amperometric immunosensor was sensitive,quickly(10 rain),disposable with low cost, fewer sample volume(2 μL) and easy preparation, which is suitable for screen - determination of trace chloramphenicol in food.