基于铂氧化铜负载多壁碳纳米管标记夹心型电化学免疫传感器

A Sandwich-type Electrochemical Immunosensor Based on Platinum Hybrid Multiwalled Carbon Nanotubes Adhered Copper Oxide

设计了一种夹心型电化学免疫传感器,以金负载二氧化锡石墨烯(GS-SnO_(2)-Au)为检测平台,铂氧化铜负载多壁碳纳米管(Pt@CuO-MWCNTs)为标记物,用于乙肝表面抗原(HBs)的定量检测。GS-SnO_(2)-Au具有较高比表面积,良好的导电性、分散性和生物相容性,有利于捕获大量抗体(Ab1)。Pt、CuO和多壁碳纳米管对H_(2)O_(2)分解均具有催化性,Pt@CuO-MWCNTs复合物能协同放大催化作用,实现多重放大信号的效果,有利于实现高灵敏检测。通过透射电镜表征GS-SnO_(2)-Au和Pt@CuO-MWCNTs的形貌特征。结果表明,基底材料和标记物材料的性能良好。在最佳实验条件下:磷酸盐pH值7.4,GS-SnO_(2)-Au的质量浓度为1 mg/mL,Pt@CuO-MWCNTs质量浓度为2 mg/mL,该免疫传感器对HBs的线性范围为0.001~100 ng/mL,检出限为0.33 pg/mL,对实际样品的加标回收率为99.8%~100%,相对标准偏差(RSD)为1.1%~1.5%。所设计的免疫传感器具有良好选择性、重现性和稳定性,在HBs的临床检测方面具有潜在应用价值。

A novel sandwich-type electrochemical immunosensor was designed for quantitative detec⁃tion of hepatitis B surface(HBs)antigen.SnO_(2) loaded graphene sheet hybridized by Au NPs(GSSnO_(2)-Au)was used as the platform.Platinum hybrid multiwalled carbon nanotubes adhered copper oxide(Pt@CuO-MWCNTs)was used as label.As the carrier material,GS-SnO_(2)-Au has larger surface area,better electrical conductivity,dispersibility and biological compatibility,which is benefit for capturing antibodies(Ab1).Pt,CuO and multiwalled carbon nanotubes could be used as catalysts for the decomposition of hydrogen peroxide,and Pt@CuO-MWCNTs could realize multiple amplified signals due to their synergy.The morphological characteristics of GS-SnO_(2)-Au and Pt@CuO-MWCNTs were observed by transmission electron microscopy(TEM).The results showed that the substrate material(GS-SnO_(2)-Au)and the marker material(Pt@CuO-MWCNTs)have ex⁃cellent properties.The synthesis of Pt@CuO-MWCNTs was further characterized by energy spec⁃trum,and the element content was also analyzed.The assembly process of the immunosensor was characterized by cyclic voltammetry(CV)and alternating current impedance.The optimal conditions were as following:pH value of phosphate buffer solution was 7.4,concentration of GS-SnO_(2)-Au was 1 mg/mL,and concentration of Pt@CuO-MWCNTs was 2 mg/mL.Under the optimal condi⁃tions,the designed immunosensor exhibited a wide linear in the range of 0.001-100 ng/mL with a low detection limit of 0.33 pg/mL for HBs.The spiked recoveries for HBs in serum samples were in the range of 99.8%-100%with relative standard deviations(RSDs)of 1.1%-1.5%.With good se⁃lectivity,reproducibility and stability,the designed immunosensor could provide potential applica⁃tions in clinical monitoring of HBs.