A Lead(Ⅱ)-Driven DNA Molecular Device for Turn-On Fluorescence Detection of Lead(Ⅱ) lon with High Selectivity and Sensitivity

摘要

A Pb~(2+)-driven DNA molecular device which is con structed based on a DNA duplex-quadruplex exchange is utilized for the highly selective and sensitive detection of Pb~(2+). The power of this DNA device originates from the excellent efficiency of Pb~(2+) for stabilizing G-quadruplexes, which makes the DNA duplex unwind thereby driving the device. This device can be reset to the original state by addition of a strong Pb~(2+) chelator DOTA, endowing the device with good reusability. In the whole process, the signal readout is modulated via a fluorescent probe binding to and being released from the G-quadruplex. Such a DNA device can serve as a novel turn-on fluorescent sensor for Pb~(2+) detection with high selectivity and sensitivity.