Electrochemiluminescence of dual excited states modulated with arginine modification of black phosphorus quantum dots

Abstract The electrochemiluminescence (ECL) is generally emitted via radiative transition of singlet or triplet excited state (S1 or T1). Herein, an ECL mechanism with the transitions of both S1 and T1 of black phosphorus quantum dots (BPQDs) was found for the first time, and an arginine modification strategy was proposed to passivate the surface oxidation defects of BPQDs, which could modulate the excited states for enhancing the ECL of BPQDs. The Arg modification led to greater spatial overlap of HOMO with LUMO and spectral shift of radiative transitions, and improved the stability of anion radical of BPQDs. The enhanced cathodic ECL was used to construct a sensitive method for conveniently evaluating the inhibiting efficiency of cyclo(RGDyK) to cell surface integrin by using RRGDS peptide modified BPQDs as signal tag. The dual excited states mediated ECL emitters provided a new paradigm for adjustable ECL generation and extended the application of ECL analysis.