Electrocatalytic reduction of a coreactant using a hemin–graphene–Au nanoparticle ternary composite for sensitive electrochemiluminescence cytosensing

A ternary composite of hemin–reduced graphene oxide–Au nanoparticles (H–RGO–Au) with a higher electrocatalytic activity for the reduction of hydrogen peroxide than that of the hemin–graphene component was synthesized and was used as a catalyst to initiate sensitive electrochemiluminescence (ECL) quenching of quantum dots (QDs) due to the electrocatalytic reduction of the coreactant H2O2. Based on this and specifically on the recognition between concanavalin A (Con A) and mannose or N-glycans on the cell surface, an ultrasensitive cytosensor for the detection of 5 cancer cells was first proposed. The designed strategy shows the possibility of expansive application of versatile ECL cytosensing platforms for the detection of many important biomolecules.