Portable Photoelectrochemical/Visualization Dual-Mode Sensor Chip for Deoxynivalenol Detection

Deoxynivalenol (DON) is a type B trichothecene mycotoxin widely existed in cereal. Herein a portable photoelectrochemical (PEC)/visualization dual-mode sensor chip was successfully developed for DON detection. By laser etching technology, different functional areas, including the photoanode, the cathode and the electrochromic area, are fabricated on the indium tin oxide (ITO) glass. Then these three areas are further respectively modified with TiO2 decorated three-dimensional nitrogen-doped graphene hydrogel (TiO2/3DNGH), Pt nanoparticles and Prussian blue. Under light illumination, the photo-induced electrons and holes of TiO2/3DNGH were separated, which may generate the photocurrent between the photoanode and the cathode. Meanwhile, the photo-induced electrons are transferred to Prussian blue on the visualization area, which will be reduced to colorless Prussian white. The binding of DON molecules and aptamers can promote electron transfer and reduce the recombination of electrons and holes. So the quantitative detection of DON can be simultaneously achieved through the photocurrents or color change. In the PEC and visualization mode, the detection range of DON is 1 fg/mL to 100 pg/mL and 1 ng/mL to 250 ng/mL respectively. This portable dual-mode sensor chip can be flexibly applied in laboratories or field test without specific instruments, which provides a powerful tool for food safety