Effects of the cross-linker on the performance and stability of enzymatic electrocatalytic films of glucose oxidase and dimethylferrocene-modified linear poly(ethyleneimine)

Abstract This work compares the performance of bioelectrocatalytic films composed of glucose oxidase, dimethylferrocene-modified linear poly (ethyleneimine) and either glutaraldehyde (GA) or ethylene glycol diglycidyl ether (EGDGE) as cross-linking agents. While GA has been widely employed as an enzyme cross-linker, its use with mediator-modified linear poly (ethyleneimine)s has not been reported. Here, we evaluate both types of polymers for use in a drop-based biosensor and a microfluidic fuel cell. In the sensing context, GA-based polymers presented higher stability at the expense of linear response range. In the energy production device, significant differences in current were not observed when comparing the performance of complete cells. We conclude that glutaraldehyde is a suitable alternative to the widespread epoxide cross-linkers for the fabrication of enzyme-containing ferrocene-modified linear poly (ethyleneimine) hydrogels.