Graphene oxide was electrodeposited on titanium (Ti-GO) and anodized titanium (ATi-GO) as label-free sensors for the detection of challenging living organisms, specificallyEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus). The graphene modification contributed to two sets of oxidation-reduction peaks in cyclic voltammograms (CVs) of bacteria growth on the electrode surfaces (ATi-GO) that resulted in increasing direct electron transfer and stimulating excretion of mediating molecules for higher electron transfer between electrodes and bacteria. Additionally, similar wave patterns of CVs were found whenE. coliorS. aureuswere grown and electrocatalyzed on ATi-GO. The results suggest that bacteria on titanium implant surfaces could be easily detected by using mediatorless ATi-GO sensors electrochemically. These finding open another interesting method in using ATi-GO asin situelectrochemical sensors for label-free, close to real-time detection of bacteria infection in orthopedic implants.
