An ultrasensitive gold nanoband aptasensor for mercury (II) detection in aquatic environment
Journal of The Electrochemical Society, 2019•iopscience.iop.org
Heavy metal contamination in aquatic environment has made great adverse impacts on
human health and environment. In this work, a label-free electrochemical gold nanoband
aptasensor (GNA) was developed using thymine-Hg 2+-thymine (T-Hg 2+-T) coordination
chemistry for Hg 2+ detection in drinking water. The gold nanoband sensor contains gold
nanoband working electrode with a band thickness of 100 nm. The nanoscale working
electrode increases the mass transfer rate and sensitivity for Hg 2+ detection. Moreover, the …
human health and environment. In this work, a label-free electrochemical gold nanoband
aptasensor (GNA) was developed using thymine-Hg 2+-thymine (T-Hg 2+-T) coordination
chemistry for Hg 2+ detection in drinking water. The gold nanoband sensor contains gold
nanoband working electrode with a band thickness of 100 nm. The nanoscale working
electrode increases the mass transfer rate and sensitivity for Hg 2+ detection. Moreover, the …
Abstract
Heavy metal contamination in aquatic environment has made great adverse impacts on human health and environment. In this work, a label-free electrochemical gold nanoband aptasensor (GNA) was developed using thymine-Hg 2+-thymine (T-Hg 2+-T) coordination chemistry for Hg 2+ detection in drinking water. The gold nanoband sensor contains gold nanoband working electrode with a band thickness of 100 nm. The nanoscale working electrode increases the mass transfer rate and sensitivity for Hg 2+ detection. Moreover, the gold nanoband sensors are cost-effective and can be easily regenerated by cutting the edge after the performance decreases dramatically compared with microelectrodes and disk electrodes. T-rich oligonucleotides modified with thiol group was self-assembled onto the working electrode through Au-S covalent bonding. In the presence of Hg 2+, oligonucleotides will capture Hg 2+, thus inducing the conformational change from single-strand to duplex-like structure that would promote electron transfer. Electrochemical impedance spectroscopy (EIS) was used to detect the Hg 2+-mediated conformational changes. By optimizing experimental conditions, the linear range of proposed biosensor is from 0.1 nM to 1 μM, and the limit of detection is 40 pM (8 ppt). Furthermore, this nanobiosensors exhibited high selectivity and a great potential to detect trace Hg 2+ in real samples from aquatic environment.
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