Graphene-quantum-dots-decorated NiAl2O4 nanostructure as supercapacitor and electrocatalyst in biosensing

Nickel aluminate-graphene quantum dots (NiAl 2 O 4 /GQDs) composite is a nanostructured material which offers synergistic behavior and multifunctionality. The high porosity, biocompatibility, low-cost preparation and electrocatalytic performance of spinel nickel aluminate has been merged with high electrical conductivity of graphene quantum dots. The NiAl 2 O 4 /GQDs composite was characterized through SEM, TEM, XPS, EDX, IR techniques and porosimetry. The cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements allowed to investigate the electrochemical performance. The composite shows enhanced supercapacitive and electrocatalytic performance with respect to the pristine NiAl 2 O 4 . The NiAl 2 O 4 /GQDs-modified gold electrode has been applied to develop an electrochemical method for glucose detection. The constructed biosensor allowed to sense glucose in serum of diabetes patients. • Synthesis of graphene-quantum-dots-decorated NiAl 2 O 4 nanostructure (NiAl 2 O 4 /GQDs). • Mesoporous material with superior supercapacitive and electrocatalytic performance. • Biosensor for glucose detection in human serum and diagnosis of diabetes mellitus.