A portable non-enzyme photoelectrochemical ascorbic acid sensor based on BiVO4 electrode under 20 W LED light

BiOI film was electrodeposited deposited on fluorine doped tin oxide (FTO), then it was transformed into a nanoporous BiVO 4 film by annealing at 420 °C. The BiVO 4 /FTO electrode is used as photoelectrochemical (PEC) sensor to detect ascorbic acid (AA) for the first time. Under illumination of low power 20 W LED lamp, the current density of the sensor increases with the increase of AA concentration. The proposed PEC sensor exhibited a sensitive detection for AA in a wide range from 5 μM to 300 μM with a low detection limit of 1 μM (S/N = 3) and sensitivity of 293 μA mM −1  cm −2 . A portable AA detection device was constructed with a 20W LED lamp as the light source, BiVO 4 /FTO electrode as an anode, Pt as a cathode, and ammeter as a photoelectric signal receiver. The concentration of AA detected by this device is close to that measured by the electrochemical workstation (RSD<10%), which makes the sensor practical and portable.