Fig. 11.

a Fabrication and functionalization of AJP graphene IDE sensor, which includes aerosol jet printing of graphene in PI substrate, thermal annealing process to generate oxygen-rich species on the graphene IDE sensor, immobilization of desired antibodies on the graphene surface, and covering of unfunctionalized areas of the graphene IDE sensor using a blocking agent to maintain the selectivity. b Non-specific adsorption test of AJP graphene IDE modified with histamine antibody against other interfering protein molecules usually present in food samples, which can be used as blocking agents that can interfere with the antibody activity. c Nyquist plots for different concentrations of histamine in fish broth sample and d calibration plot of change in charge transfer resistance v/s histamine concentrations in fish broth sample. (Source: reprinted from Parate K, Pola CC, Rangnekar S V., Mendivelso-Perez DL, Smith EA, Hersam MC. Aerosol-jet-printed graphene electrochemical histamine sensors for food safety monitoring. 2D Mater. 2020(1–13);7)