Electrochemiluminescence detection based on Ruthenium(II) tris(bipyridine) immobilised in sulfonic-functionalised titania nanoparticles by ion exchange strategy

Abstract

A novel Ruthenium(II) tris(bipyridine)-based solid-state electrochemiluminescence (ECL) sensor was developed in this paper. The sensor was fabricated by immobilising tris(2,2′-bipyridyl) ruthenium(II) (Ru(bpy)₃²⁺) in sulfonic-functionalised porous titania (TiO₂–SO₃H) nanoparticlesvia an ion exchange strategy, followed by employing environment friendly and stable biopolymer chitosan (CHIT) to entrap Ru(bpy)₃²⁺/TiO₂–SO₃H onto the ITO electrode. The prepared ECL sensor exhibited excellent ECL behaviors and a wide linear range from 7.5 × 10⁻⁹ to 2.5 × 10⁻³ M (R = 0.98) with a detection limit of 1.67 × 10⁻¹⁰ M (S/N = 3) towards 2-(dibutylamino)-ethanol (DBAE) detection. In addition, it had good reproducibility, and the relative average deviation was 0.95% of ECL intensity-time curve under continuous potential scanning for 34 cycles. It also had good long-term stability for the DBAE detection. After being used in three weeks, the sensor was able to keep over 80% activity towards 2.5 × 10⁻⁴ M of DBAE. Fabrication of the ECL sensor by this method is simple and easy, and hence has potential applications in ECL analysis and detection.