纳米金修饰电流型CA19-9免疫传感器的制备及应用

Preparation and application of colloidal gold modified amperometric CA 19-9 immunosensor

通过固定辣根过氧化酶(HRP)标记CA19-9抗体在纳米金修饰的碳糊电极制备了CA19-9安培免疫传感器.该免疫传感器在含有CA19-9抗原的磷酸盐缓冲溶液中培育后,溶液中CA19-9抗原分子和HRP标记CA19-9抗体分子免疫结合导致了传感器电流的降低.在优化的实验条件下,样品中CA19-9浓度在2～30 U/mL范围内与电流降低成线性关系,方法的检出限为1.4 U/mL.该免疫传感器表现出较好的稳定性、准确性和重现性,为临床免疫分析提供了一种快速便捷方法.

A novel immunosensor for the determination of carcinoma antigen-19-9 （CA19-9） is made by immobilization of horseradish peroxidase （HRP） labeled CA19-9 antibody on colloidal gold carbon paste electrodes. The incubation of the immunosensor in 0.1 M pH 7.0 PBS containing CA19-9 antigen was attributed to the formation of antigen-antibody complex, which blocked the electron transfer of HRP toward the electrode and resulted in significant decrease of peak current. Under optimal conditions, the decrease of the current is proportional to CA 19-9 concentration ranging from 2 to 30 U/mL with a detection limit of 1.4 U/mL. The CA 19-9 immunosen- sor shows a good accuracy and an acceptable precision and fabrication reproducibility. The proposed method provides a new promising platform for clinical immunoassay.