Real-time monitoring of biomolecular dynamics on cell membranes by quantum dot-based multicolor electrochemiluminescence

Electrochemiluminescence (ECL) offers numerous unique advantages for microscopic imaging. However, achieving real-time dynamic observation of biomolecules on cell membranes through ECL imaging remains a challenge. Herein, we present a new ECL nanoemitter for real-time multicolor imaging of biomolecules on cell membranes. The nanoemitter consists of quantum dots (QDs) with surface-immobilized glucose oxidase capable of catalyzing glucose oxidation to produce co-reactant hydrogen peroxide (H2O2). This nanoemitter enables sequential real-time imaging with a relatively high signal-to-noise ratio owing to the continuous availability of co-reactants. Therefore, by using the functionalized multicolor QDs for ECL-based single-particle tracking, the dynamic behaviors of individual biomolecules on cell membranes, including inter-molecular interactions, can be visualized in real time. This new nanoemitter is expected to facilitate investigations of the dynamics of biomolecules on cell membranes.