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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 layer of carbon nanotube (CNT) / ferrocene (Fc) / Nafion membrane was coated on the surface of the screen printed carbon electrode (SPCE), and then coated with CAP- BSA) was immobilized on the surface of [Fe3O4 (core) / Au (shell), referred to as GMP] to construct a magnetic field-controlled disposable amperometric immunosensor for CAP detection.Using scanning electron microscopy (SEM) XRFS was used to characterize the preparation of immunosensor. The electrochemical properties of the immunosensor were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The concentration of CAP was measured by competitive immunoassay . Immunosensor Different concentrations of CAP were added to 25 μL pH = 6.0 phosphate buffered saline (PBS) containing 100 ng · mL-1 anti-CAP and incubated at 25 ° C. for 6 min. The DPV reduction peak current rise percentage (CI%) and The concentration of CAP in the range of 0.2 ~ 80.0ng · mL-1 showed a linear relationship with a detection limit of 0.11ng · mL-1. It was used in the CAP test of milk samples and was compared with the standard HPLC method. The results were consistent with the recoveries of 88% 104%. The immune sensor is sensitive and fast, external magnetic field control, the sample dosage is small, can be abandoned, is expected to be used for food CAP rapid detection of trace.