Regular articleA contrivance based on electrochemical integration of graphene oxide nanoparticles/nickel nanoparticles for bilirubin biosensing

•Constructed BOx/GrONP/NiNPs/ITO/glass platform for selective and sensitive sensing.•Electrochemical studies were performed using CV and EIS.•Biosensor showed excellent detection limit, stability and wider linear range.•Measured bilirubin level in sera of apparently healthy persons and jaundice patients.

An amperometric bilirubin biosensor was fabricated by immobilization of bilirubin oxidase (BOx) on graphene oxide nanoparticles (GrONPs) that was decorated with a thin layer of nickel nanoparticles (NiNPs), and electrodeposited onto the surface of ITO electrode. The enzyme electrode was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) study. BOx/GrONP/NiNPs/ITO/glass was chosen as the bioelectrodes for amperometric detection of bilirubin. The biosensor showed an optimum response at a pH of 8.0 and 35 °C within 2 s when polarized at +0.2 V vs Ag/AgCl. The observed electrocatalytic response showed a linear dependence on bilirubin with concentration varying from 0.01 to 600 μM. The biosensor retained about 80% of its initial activity on being repeatedly utilized over a period of 180 days for about 100 times. The biosensor measured bilirubin levels in sera of apparently healthy and persons suffering from jaundice. The results have been correlated very well with those measured using a standard colorimetric technique (r = 0.99).