A Galactose Oxidase Biosensor Based on Graphene Composite Film for the Determination of Galactose and Dihydroxyacetone

A novel amperometric biosensor was developed by immobilizing galactose oxidase (GAox) on poly (L-lactide) stabilized gold nanoparticles (Au@PLLA) modified graphene nano-composite film (RGO-Au@PLLA/GAox). The direct electron transfer (DET) of GAox was achieved. Cyclic voltammetry of the GAox in the RGO-Au@PLLA film revealed a pair of well-defined and quasireversible peaks at about −0.137 V (vs. SCE), which is characterized of the Cu(II)/Cu(I) redox couple for the galactose oxidase. Amperometric response was measured as a function for the determination of galactose (GA) and dihydroxyacetone (DHA). The constructed biosensor also possesses good stability, reproducibility and anti-interference ability.