A novel OFF-ON biosensor based on nanosurface energy transfer between gold nanocrosses and graphene quantum dots for intracellular ATP sensing and tracking

An efficient strategy based on the nanosurface energy transfer (NSET) between gold nanocrosses (AuNCs) and graphene quantum dots (GQDs) for intracellular ATP sensing and tracking was first developed. GQDs and AuNCs assembled in the bases of complementary matching principle, which result in the fluorescence quenching via NSET. In the presence of ATP, aptamer recognized and combined with ATP, caused the distance change between GQDs and AuNCs. The fluorescence intensity was proportional to ATP concentration, which was represented by the equation y = 176.67 x + 335.51 (R-2 = 0.9916) with the detection limit of 0.27 mM (3 delta, n = 11). Moreover, the proposed OFF-ON sensor showed low cytotoxicity and excellent performance in intracellular ATP sensing, which will provide new possibilities for labeling of small biological molecules.