Nanomaterial-Based Electrochemiluminescence Biosensors

Abstract

Electrogenerated chemiluminescence (ECL), called electrochemiluminescence, is briefly described as chemiluminescence produced directly or indirectly as a result of electrochemical reactions. When an appropriate potential is applied to an electrode, an ECL-emitting species is generated at the electrode surface and subsequently emits light. ECL can be produced by two dominant pathways, that is, annihilation and coreactant pathway. In each case, two species are generated electrochemically, and those two species undergo homogeneous redox reactions to produce an emissive species. According to literature reports, a wide variety of molecules exhibit ECL behaviors and can be classified into three types based on their chemical nature: transition metal complexes, organic molecules, and semiconductor nanomaterials. However, the vast majority of publications are concerned with coreactant ECL pathway employing Ru(bpy)2+3 or its derivatives as the emitting species and tripropylamine or oxalate as the coreactant. Quantum dots are semiconductor nanocrystals with their size in the range of 1–10 nm.