A Sensitive and Label-Free Pb(II) Fluorescence Sensor Based on a DNAzyme Controlled G-Quadruplex/Thioflavin T Conformation
Yanli Wen,
Lele Wang,
Lanying Li,
Li Xu,
Gang Liu
Affiliations
Yanli Wen
Biometrology Laboratory, Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
Lele Wang
Biometrology Laboratory, Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
Lanying Li
Biometrology Laboratory, Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
Li Xu
Biometrology Laboratory, Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
Gang Liu
Biometrology Laboratory, Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
Pb(II) can cause serious damaging effects to human health, and thus, the study of Pb2+ detection methods to sensitively and selectively monitor Pb(II) pollution has significant importance. In this work, we have developed a label-free fluorescence sensing strategy based on a Pb(II) DNAzyme cleavage and the ThT/G-quadruplex complex. In the presence of Pb(II), a G-rich tail was cut and released from the substrate strand, which then would form a G-quadruplex structure by combination with ThT dye. The fluorescence signal increase was then measured for sensitive Pb(II) quantification with a limit of detection of 0.06 nM. Our sensor also demonstrated high selectivity against six different metal ions, which is very important for the analysis of complex samples.
