Structural changes of glucose oxidase upon interaction with gold-coated magnetic nano-particles

Structural changes of glucose oxidase (GOx), as a typical protein, upon interaction with gold-coated magnetic nano-particles (GMNPs) were studied. GMNPs were characterized by UV-vis, FTIR and SEM. Due to GMNPs interaction, obvious changes in enzyme conformation and its secondary and tertiary structures were verified using intrinsic fluorescence and circular dichroism. Moreover, Zeta potential measurement showed GMNPs surface charge shift to more negative value due to interaction with GOx. Finally, the electrochemical results revealed that while the enzyme electron transfer rate on GMNPs is higher, this process on cysteamin-GMNPs is more reversible.