Enhancing effect of black phosphorus quantum dots on electrochemiluminescence of Ir(dF(CF3)ppy)2(bpy) in ionic liquid medium and its sensing application

Abstract

Room temperature ionic liquids are increasingly used in electrochemical measurement because of their excellent properties. In the present work, a strong anodic electrochemiluminescence (ECL) of one kind of water insoluble iridium complex (Ir(dF(CF3)ppy)2(bpy)) was obtained in ionic liquid medium through immobilizing it onto the electrode via solvent evaporation method. Black phosphorus quantum dots (BPQDs) could not only enhance the anodic ECL, but also generate a new anodic ECL at lower potential. The spectral investigation indicated that BPQDs could interact with Ir(dF(CF3)ppy)2(bpy) to enhance ECL signal and induce new ECL. Dopamine could compete with Ir complex to interact with BPQDs, which exhibited apparent inhibiting effect on ECL emission. As a result, dopamine was sensitively detected in the range of 0.1 nM to 0.1 μM with a detection limit of 3.76 × 10−11 mol L−1. The present work revealed that iridium complex ECL could be obtained in ionic liquids, which provided new avenue for the fabrication of ECL biosensor.