Screening of dopamine in living cells and animal model via graphene quantum dots anchored 3D macroporous nonenzymatic sensor.

A series of three-dimensional copper oxide (CuO) inverse opals anchored with carboxylated graphene quantum dots (CuO/cGQDs) have been fabricated for non-enzymatic tracking of dopamine (DA). Heterostructures composed of various building blocks are promising to construct versatile biosensing platforms. The optimal CuO/cGQDs modified electrode demonstrates sensitivities of 243.45 μA mM-1 cm-2 (50 nM-1888.5 μM) with the practical detection limit as low as 0.5 nM in mimic physiological environment (at + 0.45 V vs. Ag/AgCl). The extraordinary tolerance to various interferents enables the practical detection of intracellular DA amount in human neural cells. On this basis, the proposed biosensor attains precise evaluation of antipsychotic drug effects on stimulated DA release. Particularly, it successfully spots fluctuation of DA in plasma and cerebrospinal fluid in murine model of Parkinson's disease, which serves as a crucial tool to understand neuropathology and symptomatology of DA-related diseases. This study developed a reliable sensing platform and is expected to be applied to physiological and pathological studies.