Sulfonic Acid-Functionalized Tetraphenylethylene-Amplified Electrochemiluminescence by Regulating π–π Interaction

Abstract

The electrochemiluminescence (ECL) effectiveness of the tris-(bipyridine) ruthenium(II) (Ru(bpy) 3 2+ ) system is hampered by aggregation-caused quenching (ACQ) in optoelectronic systems as a result of π−π accumulation of the aromatic ring structure. In this work, a negatively charged tetraphenylvinyl molecule (TPE-2SO 3 Na, TPE-4SO 3 Na) was synthesized to modify the electrode interface, and the π−π accumulation between Ru(bpy) 3 2+ molecules was transformed into the π−π interaction between Ru(bpy) 3 2+ and TPE molecules. Interestingly, the ECL signal intensity of the Ru(bpy) 3 2+ -tripropylamine (TPA) system in the presence of TPE-2SO 3 Na was increased by about 15 times due to the π−π action and electrostatic action. In comparison with traditional physical packaging with porous zeolites, metal− organic frameworks (MOFs), and covalent organic frameworks (COFs), the fabricated electrode interface modification strategy was simple and efficient to avoid π−π accumulation in aqueous solutions. Our success will inspire other researchers to investigate the supramolecular interaction (π−π interaction, electrostatic interaction, hydrophilic interaction, and host−guest interaction) at the electrode interface to amplify the ECL intensities of Ru(bpy) 3 2+ .