A Novel Surface‐tethered Analysis Method for Mercury (II) ion Detection via Self‐assembly of Individual Electrochemiluminescence Signal Units

A novel analysis strategy based on the analyte‐induced surface‐tethered (AIST) of electrochemiluminescence (ECL) signal nanoparticles was first proposed for detection of Mercury (II) ion (Hg 2+ ). In this work, luminol@Au‐cysteamine‐thymine (luminol@Au‐Cys‐T) multifunctional nanoarchitecture was designed as ECL signal units in the experimental process. Through a specific T‐Hg 2+ ‐T coordination, luminol@Au‐Cys‐T composites were gravitationally self‐assembled to the electrode surface, which was coated with tris (2‐aminoethyl) amine functionalized graphene oxide@perylene‐3,4,9,10‐tetracarboxylic acid‐thymine (GO@PTCA‐TAEA‐T) complex film. This simple strategy of AIST of signal molecules could amplify the response signal and vastly enhance the sensitivity. Under the optimum condition, the linear relationship of Hg 2+ concentration variation from 0.005 nM to 5 nM with a limit of detection (LOD) down to 0.002 nM (S/N=3), which also offered an alternative analytical approach with excellent performance of stability and selectivity. The regression equation was y=−414.52+2305.02 lgC (Hg 2+ ) (pM). This Hg 2+ ECL sensor had a good application prospects for the analysis of real samples.