College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
Biosens Bioelectron. 2016 Jul 15;81:15-22. doi: 10.1016/j.bios.2016.01.096. Epub 2016 Feb 17.
A label-free and highly sensitive electrochemical aptasensor for Pb(2+) was constructed using thionine (TH) as the signaling molecule and graphene (GR) as the signal-enhancing platform. The electrochemical sensing interface was fabricated by stepwise assembly of GR and TH on the lead (II) specific aptamer (LSA) modified electrode. Upon interaction with Pb(2+), the aptamer probe on the sensor underwent conformational switch from a single-stranded DNA form to the G-quadruplex structure, causing the GR with assembled TH released from the electrode surface into solution. As a result, the electrochemical signal of TH on the aptasensor was substantially reduced. Under the optimal experimental conditions, the attenuation of peak currents presented a good linear relationship with the logarithm of Pb(2+) concentrations over the range from 1.6×10(-13) to 1.6×10(-10)M. The detection limit was estimated to be 3.2×10(-14)M. The aptasensor also exhibited good regenerability, excellent selectivity, and acceptable reproducibility, indicating promising application in environment monitoring of lead.
一种无标记且高灵敏的电化学适体传感器用于 Pb(2+)的检测，该传感器以硫堇（TH）作为信号分子，以石墨烯（GR）作为信号增强平台。电化学传感界面是通过在 Pb(2+)特异性适体（LSA）修饰电极上逐步组装 GR 和 TH 来制备的。与 Pb(2+)相互作用后，传感器上的适体探针从单链 DNA 形式转变为 G-四链体结构，导致与 GR 组装的 TH 从电极表面释放到溶液中。结果，适体传感器上的 TH 的电化学信号显著降低。在最佳实验条件下，峰电流的衰减与 Pb(2+)浓度的对数在 1.6×10(-13)到 1.6×10(-10)M 范围内呈现出良好的线性关系。检测限估计为 3.2×10(-14)M。该适体传感器还表现出良好的可再生性、优异的选择性和可接受的重现性，表明其在铅的环境监测中有很好的应用前景。
