基于复合纳米微粒修饰电极的氯霉素快速检测用磁场可控一次性安培免疫传感器研究

A Magnetic Field Controlled and Disposable Amperometric Immunosensor for Rapid Determination of Chloramphenicol Based on Composite Nano-particle Modified Electrode

在丝网印刷碳电极(SPCE)表面涂敷一层碳纳米管(CNT)/二茂铁(Fc)/Nafion膜,进而通过外磁场作用将包被了氯霉素-牛血清蛋白(CAP-BSA)的纳米金磁微粒[Fe3O4(核)/Au(壳),简称GMP]吸附到其表面,构建了可用于CAP检测的磁场可控一次性安培免疫传感器.采用扫描电镜(SEM)、X射线荧光光谱(XRFS)表征了免疫传感器的制备过程,采用循环伏安法(CV)和示差脉冲伏安法(DPV)研究了免疫传感器的电化学性质,结合竞争性免疫分析法测定了CAP浓度.免疫传感器在含有100ng·mL-1anti-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(CI%)与CAP浓度在0.2～80.0ng·mL―1范围内呈线性关系,检测限为0.11ng·mL―1.用于牛奶样品中CAP检测并和标准HPLC方法对照,结果一致,回收率在88%～104%之间.该免疫传感器灵敏快速、外磁场可控、样品用量小、可抛弃,有望用于食品中痕量CAP快速检测.

A magnetic field controlled and disposable amperometric immunosensor was fabricated for determination of chloramphenicol （CAP） by carbon nanotube （CNT）/ferrocene（Fc）/Nafion-membrane coated on the screen-printed carbon electrodes （SPCE） and then GMP [Fe3O4（core）/Au（shell）] composite nanoparticle coated chloramphenicol-bovine serum albumin （CAP-BSA） was absorbed on it through external magnetic field.Scanning electron micrography （SEM） and X-ray fluorescence spectrometry （XRFS） were employed to characterize the construction process of the immunosensor.Cyclic voltammetry （CV） and differential pulse voltammetry （DPV） were used to study its electrochemical properties.The content of CAP was determined with competitive immunoassay.When CAP of different concentration was added in 25 μL of pH =6.0 phosphate buffer solution （PBS） containing 100 ng·mL-1 anti-CAP,the percentage of cathodic peak DPV current increase ratio （CI%） was proportional to the concentration of CAP over the range of 0.2～80.0ng·mL-1 after incubation for 6 min at 25 ℃.The detection limit was 0.11ng·mL-1.The immunosensor was employed to determine CAP in milk samples and the recovery rates exhibited a range of 88%～104%.The results were consistent to the tradition HPLC method.The proposed amperometric immunosensor was sensitive,quick,magnetic field controllable,low sample consumable and disposable,which was suitable for determining the trace chloramphenicol in food.