Molecularly Imprinting Technology and Narrow-Bandgap Semiconductors Application on Photoelectrochemical Sensors Construction

Photoelectrochemical (PEC) sensing is a promising approach to the development of low-cost and highly sensitive electroanalytical methods. These sensors are based on semiconductor materials that, under light excitation, promote electrons from the valence band to the conduction band, forming an e−/h+ pair that is used to oxidize or reduce a target molecule. The main challenges in the construction of PEC sensors are related to the need for high-energy light sources to excite the most commonly used semiconductor materials, such as TiO2 and ZnO, which have large bandgap values, in addition to low selectivity. In this context, narrow bandgap semiconductors, such as BiVO4, have been used as an alternative material due to their ability to promote the e−/h+ pair under excitation by visible light. For improving the selectivity of PEC sensors, a favorable strategy is the use of molecularly imprinting technology, either in imprinting the semiconductor with the target analyte or in the association of semiconductors with molecularly imprinted polymers (MIPs). Additionally, MIPs can be synthesized in the presence of carbonaceous materials, e.g., multiwalled carbon nanotubes, by surface imprinting strategies, which may improve the electrical conductivity of the sensor and the separation of the e−/h+ pair. Thence, this review aims to provide an overview of the use of BiVO4, and the synthesis strategies and advantages of using molecularly imprinted semiconductors and/or polymers in the construction of PEC sensors.