Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
Anal Chem. 2020 Oct 20;92(20):14069-14075. doi: 10.1021/acs.analchem.0c03110. Epub 2020 Sep 30.
An ultrasensitive controlled release system electrochemical aptasensor (CRSEA) has been developed for supersensitive determination of mercury ions (Hg), using gold nanoparticle-linked specific single-stranded DNA (Au NPs-ssDNA) as a molecular gate and mesoporous silica nanocontainers (MSNs) as containers. MSNs have a rich porous structure, thus entrapping the toluidine blue (TB) molecules inside. It is worth noting that Hg binds to the ssDNA with multiple thymine (T) and induces the ssDNA to form a hairpin structure, which makes the separation of the Au NPs-ssDNA from the MSNs. Eventually, the stored TB molecules were released from MSNs. The electron transfer signals of TB were detected stably by a differential pulse voltammetry (DPV) detection method, which are correlated with the concentration of Hg. Therefore, the wide linear range (10 pM-100 μM) and low limit of detection (2.9 pM) were obtained, and the system also displayed an apparent electrochemical signal response in real sample detection and showed a promising possibility in actual monitoring.
一种超灵敏的控制释放系统电化学适体传感器 (CRSEA) 已经被开发出来，用于超灵敏地测定汞离子 (Hg)，使用金纳米粒子连接的特定单链 DNA (Au NPs-ssDNA) 作为分子门和介孔硅纳米容器 (MSNs) 作为容器。MSNs 具有丰富的多孔结构，因此将甲苯胺蓝 (TB) 分子包裹在内部。值得注意的是，Hg 与 ssDNA 上的多个胸腺嘧啶 (T) 结合，并诱导 ssDNA 形成发夹结构，从而使 Au NPs-ssDNA 与 MSNs 分离。最终，储存的 TB 分子从 MSNs 中释放出来。TB 的电子转移信号通过差分脉冲伏安法 (DPV) 检测方法稳定地检测到，该方法与 Hg 的浓度相关。因此，该系统获得了较宽的线性范围 (10 pM-100 μM) 和较低的检测限 (2.9 pM)，并且该系统在实际样品检测中显示出明显的电化学信号响应，在实际监测中具有广阔的应用前景。
