Indium tin oxide bipolar electrodes modified with Pt nanoparticles encapsulated inside dendrimers as sensitive electrochemiluminescence platforms

Abstract

• Both poles of a closed bipolar electrode (BPE) were modified with catalytic Pt nanoparticles. • The dual-modified BPE showed amplified electrochemiluminescence (ECL) of Ru(bpy) 3 2+ . • The amplified ECL was ascribed to simultaneous catalysis on the both BPE poles. • The dual-modified BPE was utilized for bipolar ECL imaging analysis of H 2 O 2 . Here, we report highly enhanced electrochemiluminescence (ECL) from a closed bipolar electrode (BPE) system consisting of an indium tin oxide (ITO) microband BPE whose both poles were modified with catalytic Pt nanoparticles encapsulated inside dendrimers. The closed BPE-based ECL sensing system generated sensitive and stable ECL emission under a mild driving voltage owing to simultaneous catalysis of both anodic ECL and cathodic sensing reactions on the reporting pole and the detecting pole of the dual-modified ITO microband BPE, respectively. We demonstrated much amplified ECL of Ru(bpy) 3 2+ /tripropylamine with the closed BPE-based ECL systems having the dual-modified ITO BPEs; specifically, ∼4 times higher sensitivity than that of the ECL systems having unmodified ITO BPEs for bipolar ECL imaging analysis of H 2 O 2 as a model marker of metabolism. In addition, the closed BPE-based ECL systems exhibited stable and steady ECL emission even upon 50 consecutive applications of a driving voltage of 2.3 V for robust and extended bipolar ECL imaging analysis of H 2 O 2 .