基于二硫化钼/纳米金和硫堇/纳米金信号放大的雌二醇电化学适配体传感器

MoS2-Gold Nanoparticles and Thionine-gold Nanoparticle Based Signal-enhanced Electrochemical Aptasensor for the Detection of 17β-Estradiol

构建了一种新型的基于二硫化钼/纳米金和硫堇/纳米金信号放大的检测17β-雌二醇的电化学适配体传感器.利用巯基自组装技术将17β-雌二醇的适配体探针DNA固定在二硫化钼/纳米金修饰玻碳电极表面,与末端带巯基的部分互补DNA链杂交,将硫堇/纳米金电化学指示剂自组装在杂交后的双链DNA上,制备了17β-雌二醇电化学适配体传感器.二硫化钼/纳米金复合材料增加了电极的有效表面积和DNA探针的固定量.纳米金作为信号物质载体负载硫堇,实现了电化学指示剂的信号放大.加入目标物17β-雌二醇后,目标物与适配体DNA特异性结合,导致互补DNA链脱落,双链上结合的硫堇/纳米金电化学指示剂数量减少,电化学信号降低.实验结果表明,在1.0×10^-14~5.0×10^-12mol/L范围内17β-雌二醇浓度与峰电流的线性关系良好,检出限为4.2×10^-15mol/L(S/N=3).该传感器可望用于其它环境激素类物质的检测.

An ultrasensitive electrochemical aptasensor for the determination of 17β-estradiol( E2) was constructed based on signal-enhanced with molybdenum disulfide nanosheet( MoS2)-gold nanoparticles( GNPs)and thionine-gold nanoparticle( THI/GNPs) conjugates as electrochemical indicator. The aptasensor was fabricated in sequence by self-assembling of thiolated aptamer DNA probes onto the surfaces of the modified electrodes,and then hybridized with thiolated complementary strand DNA( csDNA) to form double-stranded DNA( ds DNA) duplex. MoS2-GNPs nanoparticles were used to increase the electrode surface area,enhance the electron transfer rate and amplify the sensor signal. GNPs as a biomarker load thionine,implements the electrochemical indicator signal amplification. E2 can be detected in the concentration range from1. 0×10^-14 mol/L to 5. 0×10^-12 mol/L,and down to levels as low as 4. 2×10^-15 mol/L. This study may offer a new approach with good analytical properties and potential applications.