Mesoporous Cu-doped BaTiO3-G-SiO2-based easy-to-use electrochemical biosensor for sensing pathogenic S. aureus biofilm

Biofilms are primary causes of clinical bacterial infections. They are resistant to typical amounts of antibiotics, necessitating very high doses for elimination. Therefore, it is imperative to establish sensitive, rapid, and timely methods for the detection of Staphylococcus aureus (S. aureus) biofilm. The aim of this research was to develop an easy-to-use electrochemical sensor for sensing pathogenic S. aureus biofilms. We developed mesoporous Cu-doped BaTiO3-G-SiO2 (CBTGS)-based electrodes to investigate their electrochemical detection ability for S. aureus biofilms. Results revealed that mesoporous CBTGS electrode in biosensing devices provided high sensitivity and stability for electrochemical detection of S. aureus biofilms. When the mesoporous morphology of CBTGS was compared to that of Cu-doped BaTiO3-G or Cu-doped BaTiO3, it showed a higher surface area with more active sites for attaching S. aureus biofilms, leading to its higher electron transfer resistance. As a result, it enabled rapid detection. A linear relationship between the increment in electron transfer resistance and the logarithmic value of S. aureus biofilm concentration was observed between 40 and 200 µL. The limit of detection was observed to be 5 µL. Finally, a good selectivity versus S. enterica (Salmonella enterica) and P. aeruginosa (Pseudomonas aeruginosa) was obtained for our developed mesoporous CBTGS, demonstrating its specificity towards only Staphylococcus aureus biofilms.