Related Experiment Video
Updated: May 11, 2026

An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Aptamer functionalized gold nanoparticles based fluorescent probe for the detection of mercury (II) ion in aqueous
Daidi Tan1, Yue He, Xiaojing Xing
1Key Laboratory of Analytical Chemistry for Biology and Medicine, College of Chemistry and Molecular Sciences, Wuhan Institute of Biotechnology, Wuhan University, Wuhan 430072, China.
Abstract:
A method is proposed for the detection of Hg(2+) using Hg(2+) specific DNA (MSD) functionalized gold nanoparticles (AuNPs) based on the formation of T-Hg(2+)-T complex and the excellent quenching fluorescence property of AuNPs. The MSD is rich in thymine (T) and readily forms T-Hg(2+)-T configuration in the presence of Hg(2+). The MSD which is labeled with a fluorescein (FAM) at the 3'-end and a thiol at the 5'-end is bounded to the AuNPs through Au-S covalent bonds to form the probes (AuNPs-MSD). Hg(2+) detection can be easily realized by monitoring the change of fluorescence signal of AuNPs-MSD probes. Hg(2+) can be detected in a range of 0.02-1.0 µM with a detection limit of 16 nM. Besides, the assay shows excellent selectivity for Hg(2+) over other metal cations such as Fe(3+), Ca(2+), Mg(2+), Mn(2+), Cr(3+), Ni(2+), Cu(2+), Co(2+) and Pb(2+). The major advantages of this Hg(2+) assay are its water-solubility, simplicity, low cost and high sensitivity. Moreover, this method provides a potentially useful method for the Hg(2+) detection in aqueous solution.
