A Signal Amplification Strategy Using ATP as a Co‐Reaction Accelerator for the Electrochemiluminescence of Ru(bpy)₃²⁺/HEPES System and Detection of Iodide Anions**

Abstract

Adenosine triphosphate is an important biological molecule that provides energy and substrate for various cellular biochemical processes,it's ubiquitous in our lives. In this work, a novel electrochemiluminescence (ECL) sensor composed of Ru(bpy) 3 2 + , 2-[4-(2-hydroxyethyl)piperazin-1-yl] ethanesulfonic acid (HEPES) and adenosine 5'-triphosphate disodium salt (ATP) was developed for the first time. In this ECL system, Ru(bpy) 3 2 + was used as the luminophore, HEPES buffer was served as the co-reactant, and ATP was added to the system to amplify the luminous signal to investigate the ECL behavior. Through fluorescence spectroscopy, ECL spectroscopy, and cyclic vol-tammetry (CV), it can be hypothesized that the possible ECL mechanism is that ATP acts as an advanced co-reaction promoter to accelerate the oxidation of HEPES to HEPES + * , more HEPES * can be generated, which then reacts with oxidized Ru(bpy) 3 3 + to emit stronger ECL signals. Subsequently, the influence of the ATP concentrations and the CV scanning speed was investaged. Moreover, it was observed that I À could quench the ECL intensity, the linear relationship range of I À concentration is from 10 À 3 to 10 À 6 m, the limit of detection is 3.7 × 10 À 8 m (signal/noise = 3), therefore, a new, highly sensitive, and selective ECL approach for I À detection was created.