Anodic Electrochemiluminescence of Carbon Dots Promoted by Nitrogen Doping and Application to Rapid Cancer Cell Detection

In this work, a kind of novel nitrogen doped hydrazide conjugated carbon dots (NHCDs) with strong anodic electrochemiluminescence (ECL) at a low excitation potential were synthesized via a one-step solvothermal approach and applied to construct biosensor for rapid cancer cell detection. The nitrogen doping induced a shift of the highest occupied molecular orbital (HOMO) to the upper energy level thus lowered the anodic ECL excitation potential of carbon dots. Especially, comparing to nondoped hydrazide conjugated carbon dots, NHCDs exhibited 2.5-fold high ECL quantum efficiency because the lower potential could reduce notably the side reactions in the ECL process. Using the high-performance NHCDs to functionalize the electrode surface, a brief ECL biosensor was fabricated to detect the cell-secreted hydrogen peroxide, which could rapidly distinguish cancer cells from normal cells. What is more, the prepared NHCDs, as the combination of low excitation potential, strong ECL emission, and good biocompatibility, were expected to be popular luminophors for clinical diagnose of cancer and monitoring the pharmacodynamics of anticancer drugs.