牛奶中痕量氯霉素快速检测的纳米修饰一次性安培免疫传感器研究

A novel disposable amperometric immunosensor modified by nano-particles for the rapid detection of trace chloramphenicol in milk

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.