Hot electron-induced electrogenerated chemiluminescence of Ru(bpy)32 + chelate at a pointed active metal cathode in fully aqueous solutions

•Hot electron injection into aqueous electrolyte solutions•Generation of hydrated electron•Electrochemiluminescence of tris(2,2′-bipyridine)ruthenium(II) chelate•Sensitive detection of luminescent labels

Tris(2,2′-bipyridine)ruthenium(II) chelate exhibits strong electrogenerated chemiluminescence during cathodic high-voltage pulse-polarization of pointed Pt electrode in aqueous solutions. The present method is based on a field emission or other type of tunnel emission of hot electrons into an aqueous electrolyte solution. The method allows the detection of tris(2,2′-bipyridine)ruthenium(II) and its derivatives below nanomolar concentration levels and yields linear log-log calibration plots spanning several orders of magnitude of concentration.