A Sensitive and Label-Free Pb(II) Fluorescence Sensor Based on a DNAzyme Controlled G-Quadruplex/Thioflavin T Conformation

• Main Authors: Yanli Wen, Lele Wang, Lanying Li, Li Xu, Gang Liu
• Format: Article
• Language: English
• Published: MDPI AG 2016-12-01
• Series: Sensors
• Subjects: DNAzyme; heavy metal ions; lead ion; thioflavin T (ThT)
• Online Access: http://www.mdpi.com/1424-8220/16/12/2155

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.