A Photoelectrochemical Platform Based on Polyaniline-Modified Titanium Dioxide Facet Heterostructure

A photoelectrochemical (PEC) electrode for glucose detection was built based on polyaniline (PANI) modified titanium dioxide heterojunction (FH-TiO₂) structures. Ultrathin titanium dioxide (TiO₂) nanosheets are assembled onto rutile nanorods (TiO₂ NRs). Experiments show that the main exposed faces of these nanosheets are (101) or (111) crystal planes. Proven by theoretical calculation, the bottom of the conduction band (CB) of (111) is 0.15 eV lower than the bottom of the conduction band of (101). Therefore, when the material is excited by light, photogenerated electrons are able to transfer from the conduction band of (101) to the conduction band of (111). PANI was introduced as a medium to effectively conduct photogenerated charges between glucose oxidase and titanium dioxide. A photoelectric detection electrode for glucose was fabricated by loading glucose oxidase onto PANI@FH-TiO₂. This electrode showed excellent performance in 0.2-1.0 mM linear range with a sensitivity 15.63 μA mM^-1 cm^-2 and 1.0-15.0 mM linear range with a sensitivity of 1.42 μA mM^-1 cm^-2.