An Electrochemiluminescence Biosensor for Determination of Pb2+ Based on G-Quadruplex of Aptamer Probe

作者：Wei Xiao-Ping; Yang Feng; Ding Fan; Li Jian-Ping^*

来源：Chinese Journal of Analytical Chemistry, 2014, 42(7): 942-947.

DOI：10.1016/S1872-2040(14)60750-7

• Aptamer
• Pb2+ sensor
• Electrochemiluminescence
• Quantum dots
• "Turn on" model
• G-quadruplex

A "turn on" model of electrochemiluminescence Pb2+ biosensor based on G-quadruplex of aptamer probe was developed by using quantum dots as labels. The biosensor was prepared by immobilizing a hairpin aptamer probe with a thiol group at 5'-end and an amino group at 3'-end on gold electrode via an Au-S bond. In the presence of Pb2+, the G-rich hairpin aptamer probe opens the stem-loop and forms G-quadruplex, which exposes the amino group at 3'-end that could covalently link to CdS quantum dots with carboxyl group on the surface. The fabrication and reaction process of the Pb2+ biosensor were characterized. The responsive electrochemiluminescence intensity was linearly related to the Pb2+ concentrations in the range of 2.0 x 10(-10)-5.0 x 10(-8) M, with a detection limit of 3.74 x 10(-11) M. The ECL biosensor has high sensitivity, good selectivity, satisfying stability and repeatability.

• 出版日期2014-7
• 单位桂林理工大学