Electrogenerated chemiluminescence of tris(2,2′ bipyridine)ruthenium(ii) using common biological buffers as co-reactant, pH buffer and supporting electrolyte

Abstract

A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2′-bipyridine)ruthenium(II) ([Ru(bpy)₃]²⁺). These were found to be very attractive as “multi-tasking” reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)₃]²⁺ in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.