Multifunctional PTCA/GO for a Glucose-Driven Electrochemiluminescence Biosensor

The self-decomposition of hydrogen peroxide inevitably hinders the sensitivity and luminous efficiency of 3,4,9,10-perylene tetracarboxylic acid (PTCA) in electrochemiluminescence (ECL) systems. For the first time, as a new and advanced coreactant, glucose was efficiently activated by PTCA/graphene oxide (PTCA/GO) to generate numerous reactive oxygen species (ROS) for triggering the ECL emission of PTCA. PTCA/GO exhibits excellent glucose oxidase-like and catalase (CAT)-like activities to achieve the in situ generation and accumulation of hydroxyl radicals (·OH) and superoxide radicals (O₂^•-). Meanwhile, the oxygen reduction reaction (ORR) of PTCA/GO follows a four-electron pathway to produce more ·OH and O₂^•-. The as-accumulated ·OH and O₂^•- subsequently react with PTCA anion radicals (PTCA^•-) to emit strong ECL signals. Finally, a novel ECL biosensor was fabricated based on the PTCA/GO-glucose system for the ultrasensitive detection of glucose and alkaline phosphatase (ALP).