School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, People's Republic of China.
School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, People's Republic of China.
Talanta. 2018 Jun 1;183:237-244. doi: 10.1016/j.talanta.2018.02.087. Epub 2018 Mar 19.
An ultrasensitive photoelectrochemical (PEC) aptasensor for lead ion (Pb) detection was fabricated based on MoS-CdS:Mn nanocomposites and sensitization effect of CdTe quantum dots (QDs). MoS-CdS:Mn modified electrode was used as the PEC matrix for the immobilization of probe DNA (pDNA) labeled with CdTe QDs. Target DNA (tDNA) were hybridized with pDNA to made the QDs locate away from the electrode surface by the rod-like double helix. The detection of Pb was based on the conformational change of the pDNA to G-quadruplex structure in the presence of Pb, which made the labeled QDs move close to the electrode surface, leading to the generation of sensitization effect and evident increase of the photocurrent intensity. The linear range was 50 fM to 100 nM with a detection limit of 16.7 fM. The recoveries of the determination of Pb in real samples were in the range of 102.5-108.0%. This proposed PEC aptasensor provides a new sensing strategy for various heavy metal ions at ultralow levels.
基于 MoS-CdS:Mn 纳米复合材料和 CdTe 量子点 (QDs) 的敏化效应，构建了用于检测铅离子 (Pb) 的超灵敏光电化学 (PEC) 适体传感器。MoS-CdS:Mn 修饰电极被用作 PEC 基质，用于固定标记有 CdTe QDs 的探针 DNA (pDNA)。目标 DNA (tDNA) 与 pDNA 杂交，使 QDs 通过棒状双螺旋远离电极表面定位。在 Pb 存在下，pDNA 构象发生变化形成 G-四链体结构，导致标记的 QDs 靠近电极表面，产生敏化效应，光电流强度明显增加。线性范围为 50 fM 至 100 nM，检测限为 16.7 fM。实际样品中 Pb 的测定回收率在 102.5-108.0%范围内。该提出的 PEC 适体传感器为各种重金属离子在超低水平下提供了一种新的传感策略。
