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目的以羟基磷灰石-壳聚糖(HA-CHIT)纳米复合物修饰玻碳电极,磺胺甲噁唑抗体为探针,探讨一种新型的电化学免疫传感器检测磺胺甲噁唑(SMX)。方法用滴涂法将HA-CHIT纳米复合物修饰在玻碳电极表面制成特异的电化学免疫传感器。用循环伏安法对修饰电极的性能进行表征。在电极上固定SMX抗体作为探针,依据免疫竞争法,样品SMX与辣根过氧化物酶标记SMX竞争电极上的抗SMX多克隆抗体,采用差分脉冲伏安法对SMX进行检测。结果免疫反应时间为20 min、孵育温度37℃、检测底液pH5.5时,电流响应最灵敏。线性范围为1.0×10-7～5.0×10-4mg/ml,线性方程为△I=9 695.2c+0.6511,相关系数为0.9909;最低检出限为8.54×10-8mg/ml;相对标准偏差(RSD)<5%。结论基于HA-CHIT纳米复合物修饰玻碳电极制得的电化学免疫传感器具有线性范围宽、检出限低、快速灵敏等优势,可实现对磺胺甲噁唑的快速测定,具有良好的应用前景。
OBJECTIVE To investigate the detection of sulfamethoxazole (SMX) by a new electrochemical immunosensor with HA-CHIT nano-composite modified glassy carbon electrode and sulfamethoxazole antibody as probes. Methods HA-CHIT nanocomposites were modified on the surface of glassy carbon electrode by dripping method to form specific electrochemical immunosensor. The performance of the modified electrode was characterized by cyclic voltammetry. SMX antibody was immobilized on the electrode as a probe. According to the competitive immunoassay method, sample SMX competed with horseradish peroxidase labeled SMX for the anti-SMX polyclonal antibody, and differential pulse voltammetry was used to detect SMX. Results The immune reaction time was 20 min and the incubation temperature was 37 ℃. When pH was 5.5, the current response was the most sensitive. The linear range was 1.0 × 10-7 ~ 5.0 × 10-4mg / ml, the linear equation was △ I = 9 695.2c + 0.6511, the correlation coefficient was 0.9909, the lowest detection limit was 8.54 × 10-8mg / ml. The relative standard deviation (RSD) <5%. Conclusion Electrochemical immunosensor based on HA-CHIT nanocomposite modified glassy carbon electrode has the advantages of wide linear range, low detection limit and fast sensitivity, which can be used for the rapid determination of sulfamethoxazole and has a good prospect of application .