基于金银纳米立方体构建高灵敏CA-153传感器的研究

癌抗原-153(CA-153)是乳腺癌最重要的特异性标志物。利用CA-153与其抗体之间的特异性识别性构建"三明治"夹心结构的免疫传感器,在玻碳电极上修饰金纳米/氧化石墨烯复合材料,通过纳米金和CA-153抗体之间的吸附作用,将抗体固定于电极表面,以牛血清白蛋白封闭非特异性吸附位点。金银(AuAg)纳米立方体标记CA-153二抗,标记的AuAg纳米立方体催化过氧化氢氧化电子媒介体硫堇,采用差分脉冲伏安法检测CA-153的电化学信号。在最优条件下,此传感器的响应电流与CA-153浓度的对数在2.0×10~(-5)~100 U/mL范围内呈良好的线性关系,检出限(S/N=3)为7.0×10~(-6)U/mL。对实际血清样品进行加标回收实验,回收率为92.2%~110.2%,相对标准偏差不大于8.7%。

A Highly Sensitive CA-153 Sensor Based on AuAg Cube Nanomaterial

Cancer antigen-153(CA-153) was very significant specific tumor marker.An Au nanoparticles/graphene oxide(Au NPs/GO)-based electrochemical immunosensing platform was fabricated for the sensitive detection of CA-153 by the sandwich immunoassay protocol.Au NPs/GO composite material was used to modify the glassy carbon electrode.CA-153 antibody was anchored on the surface of Au NPs by the absorbtion of Au NPs and CA-153 antibody.Bovine Serum Albumin(BSA) was used to block possible remaining active sites of nanomaterials and avoid the nonspecific adsorption.AuAg cube nanomaterial available to catalyze the reduction of hydrogen peroxide was used to lable antibody(Ab2).The electrochemical signals derived from the carried AuAg cube toward the reduction of H2O2 using the thionine as electron mediator,and were measured by differential pulse voltammetry.Under the optimized experimental conditions,the linear range and the detection limit(S/N=3) of CA-153 immunosensor were 2.0×10-5-100 U/mL and 7.0×10-6 U/mL,respectively.The proposed method was applied in the detection of CA-153 in spiked human serum samples with recoveries of 92.2%-110.2% and RSD not more than 8.7%.