Titania nanotube-modified screen printed carbon electrodes enhance the sensitivity in the electrochemical detection of proteins

• Titania nanotubes substantially enhances sensitivity towards detection of proteins
• Current variations measure protein concentrations in the electrochemical sensor
• Staphylococcus aureus PBP2a could be reproducibly detected in crude cell lysates

The use of titania nanotubes (TiO2-NT) as the working electrode provides a substantial improvement in the electrochemical detection of proteins. A biosensor designed using this strategy provided a robust method to detect protein samples at very low concentrations (Cprotein ca 1 ng/μl). Reproducible measurements on protein samples at this concentration (Ip,a of 80 + 1.2 μA) could be achieved using a sample volume of ca 30 μl. We demonstrate the feasibility of this strategy for the accurate detection of penicillin binding protein, PBP2a, a marker for methicillin resistant Staphylococcus aureus (MRSA). The selectivity and efficiency of this sensor were also validated using other diverse protein preparations such as a recombinant protein tyrosine phosphatase (PTP10D) and bovine serum albumin (BSA). This electrochemical method also presents a substantial improvement in the time taken (few minutes) when compared to conventional enzyme-linked immunosorbent assay (ELISA) protocols. It is envisaged that this sensor could substantially aid in the rapid diagnosis of bacterial infections in resource strapped environments.