"Turn-On" Chemiluminescence Sensor for the Highly Selective and Ultrasensitive Detection of Hg2+ Ions Based on Interstrand Cooperative Coordination and Catalytic Formation of Gold Nanoparticles

Monitoring the levels of potentially toxic metal ions such as Hg2+ in aquatic ecosystems is important because this ion can have severe effects on human health and the environment. Thus, a novel chemiluminescence (CL) sensor is developed for the highly selective and ultrasensitive detection of Hg2+ ions in aqueous solution, based on thymine-Hg2+-thymine (T-Hg2+-T) coordination chemistry and subsequent formation of gold nanoparticles (Au NPs) in a HAuCl4/NH2OH reaction. The thus-formed Au NPs trigger the reaction between luminol and AgNO3, producing CL emission. This novel CL technique has several advantages including high sensitivity (0.01 ppb) and selectivity over a spectrum of interfering metal ions. In view of these advantages, as well as the cost-effective, minimized working steps and portable features of the CL techniques, we expect that this CL sensor will be a promising candidate for the field detection of toxic Hg2+ ions in environment, water, and food samples.