One-pot scalable synthesis of rGO/AuNPs nanocomposite and its application in enzymatic glucose biosensor

Abstract A nanocomposite, rGO/AuNPs, was synthesized simultaneously using one-pot approach with gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) within gelatin which used as a reducing and stabilizing agent. Then, the fabricated nanocomposites were characterized by UV-Vis, transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The optimal nanocomposite was determined using electrochemical approaches. After facile and eco-friendly synthesis of rGO/AuNPs nanocomposites, it was used to fabricate the bioanode of enzymatic glucose biosensors. After drop-casting the nanocomposites on a screen-printed electrode (SPE), the glucose oxidase (GOx) was immobilized on the pre-treated SPE through a protein cross-linking approach using glutaraldehyde (GA) as a crosslinking reagent and 2,5-dihydroxybenzaldehyde (DHB) as a mediator to improve the electrochemical performance. Then, electrochemical performance of enzyme immobilized nanocomposites was studied using the potentiostat. The results demonstrate that the enzymatic biosensor made of rGO/AuNPs nanocomposites showed enhanced the sensitivity of selectivity for detection of glucose. Graphical Abstract