Highly flexible and robust light-addressable photoelectrochemical sensor based on BiVO4-MWCNTs for enzyme-free high-throughput detection of sweeteners

On-site high-throughput photoelectrochemical (PEC) detection of sweeteners in foods and drinks by cost-effective portable devices is highly desirable for food safety and health management. However, current high-throughput PEC sensors usually suffer from high costs, complex fabrication processes, or poor mechanical properties. Here, a highly flexible and robust light-addressable PEC sensor for the enzyme-free high-throughput detection of sweeteners using single-channel electrochemical analyzers is reported. This solar cell-type sensor consists of a bismuth vanadate-multi-walled carbon nanotubes (BiVO 4 -MWCNTs) photoanode and a silver/silver chloride (Ag/AgCl) cathode. Amongst these electrode materials, BiVO 4 exhibits strong photochemical oxidation capacity towards various sugar and sugar substitute sweeteners, MWCNTs enhance the film-formation ability and the photo-induced electron transfer process of BiVO 4 , while Ag/AgCl greatly simplifies the structure of the sensor and promotes its PEC response by efficient cathodic compensation reaction. The resulting PEC sensor has good mechanical and PEC properties, and allows the rapid high-throughput detection of typical sweeteners such as glucose (GLU) and erythritol (ERY) with a calibration range of 10–240 mg/L. Moreover, the detection throughput of the sensor can be easily extended by connecting a series of sensors in parallel. The present work thus establishes a portable and flexible PEC platform for the rapid high-throughput detection of sweeteners in foods and drinks.