Ionic liquid modified SiO2 nanoparticles as coreactant of Ru(bpy)32+ ECL and its application in the detection of glutathione

Abstract

In this work, a novel electrochemiluminescence (ECL) signal amplification strategy was proposed based on SiO2nanoparticles modified with ionic liquids (ILs) as a coreactant for Ru(bpy)32+ ECL. The defects of silica nanospheres could combine with H2O and act as the oxidation center of ECL reaction to enhance the anodic ECL of Ru(bpy)32+. The modification of ILs on the surface of SiO2 nanoparticles could further enhance Ru(bpy)32+ ECL due to its excellent conductive activity and the adsorption ability for Ru(bpy)32+. ECL resonance energy transfer (RET) between MnO2 nanosheets and Ru(bpy)32+ could efficiently quench the ECL signal. In the presence of glutathione (GSH), the redox reaction between MnO2 nanosheets and GSH could cut the pathway for the RET and restore the ECL signal. As a consequence, the designed sensor exhibited outstanding performance for the detection of GSH in the concentration range of 50 nM to 50 μM with a low detection limit of 41.8 nM. Importantly, this work explored the possibility of using green and non-toxic coreactants for ECL, which will provide new avenue for the fabrication of biosensor.