Visible-light driven biofuel cell based on hierarchically branched titanium dioxide nanorods photoanode for tumor marker detection

• Visible light driven photoelectrochemical biofuel cell (PEBFC) was constructed to implement PSA detection.
• Hierarchical branched TiO2 nanorods (B-TiO2 NRs) were synthesized.
• CdS QD was utilized to sensitized B-TiO2 NRs to harvest photons in the visible region.
• 3D flower-like hierarchically carbon material (FCM) was served as nanocarrier to immobilize AuNPs and BOD.

In this work, a novel sensing platform based on visible light driven biofuel cell (BFC) has been facilely designed for sensitive detection of prostate-specific antigen (PSA) with the photo-response bioanode, realizing the dual route energy conversion of light energy and chemical energy to electricity. The hierarchical branched TiO2 nanorods (B-TiO2 NRs) decorated with CdS quantum dots (QDs) act as the substrate to confine glucose dehydrogenase (GDH) for the visible light driven glucose oxidation at the bioanode. Three dimensional flowers like hierarchical carbon/gold nanoparticles/bilirubin oxidase (3D FCM/AuNPs/BOD) bioconjugate served as biocatalyst for O2 reduction at the biocathode. With an increase in the concentration of PSA, the amount of BOD labels on biocathode increases, thus leading to the higher current output of the as-proposed visible light driven BFC. Based on this, this sensing platform provide great performance in sensitivity and specificity, increasing linear detection range from 0.3 pg mL−1 to 7 μg mL−1 with a detection limit of 0.1 pg mL−1. Most importantly, our new sensing strategy provided a simple and inexpensive sensing platform for tumor markers detection, suggesting its wide potential applications for clinical diagnostics.