基于AgI模拟酶纳米材料构建阻抗型免疫传感器用于检测癌胚抗原

目的 设计一种基于AgI模拟酶纳米材料的阻抗型免疫传感器,对血清样品中的癌胚抗原(CEA)进行高灵敏检测.方法 合成一种壳聚糖修饰的碘化银(CS-AgI)纳米材料,利用透射电镜(TEM)和傅里叶红外光谱(FTIR)法对合成的CS-AgI进行表征,以CS-AgI为信号标记物修饰CEA抗体,采用夹心式免疫分析法在金电极表面制备一种高效、灵敏的电化学免疫传感器,采用电化学工作站定量分析检测所构建免疫传感器的电化学性能.结果 成功合成CS-AgI纳米颗粒,颗粒呈球形,粒径约为100 nm.以CS-AgI纳米颗粒为信号标记物构建的免疫传感器在pH7.0的磷酸盐缓冲液中检测CEA时表现出良好的电化学性能,其交流阻抗响应值与样品中的CEA浓度的对数呈线性增加趋势,并在CEA浓度为0.1～80 ng/mL范围内展现出良好的线性关系(r=0.996),检测限达到0.05 ng/mL.结论 基于AgI模拟酶纳米材料构建的阻抗型免疫传感器可以高灵敏检测CEA,同时具有较好的精确性、重现性和选择性,为癌症的早期诊断和早期治疗提供了实验依据.

A novel impedimetric immunosensor based on AgI mimic enzyme nanomaterial for detecting carcinoembryonic antigen

Objective To highly sensitive detection of carcino embryonic antigen in serum, a novel impedimetric immunosensor was constructed. Methods Chitosan modified AgI nanomaterials (CS-AgI) were synthesized, which was characterized by transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). Then, by utilizing CS-AgI labeled CEA antibody as tags, a novel impedimetric immunosensor was built on the gold electrode based on the sandwich-type immunoassay. The electrochemical signals were monitored by electrochemical workstation and the concentration of CEA in sample was quantitatively analyzed. Results Under optimal conditions, the electrochemical impedance values increased with the increasing of CEA levels in sample, which exhibited linear in the range of 0. 1 ng/mL - 80 ng/mL with a detection limit of 0.05 ng /mL. Conclusion The developed electrochemical immunosensor owned acceptable selectivity, repeatability and stability and could fulfill the potential application for analyzing real serum samples in future.