Photoelectrochemical determination of phloroglucinol based on a combination of a ceramic perovskite and bismuth...

Phloroglucinol (PL) or 1,3,5-trihydroxybenzene is a phenolic compound used therapeutically for its antispasmodic properties. However, an overdose or prolonged exposure to PL can have harmful effects on human health. This work describes for the first time the development of a photoelectrochemical (PEC) sensor to determine PL. The proposed sensor is based on a fluorine-doped tin oxide (FTO) substrate modified with bismuth calcium tantalate (CaBi₂Ta₂O₉), a ceramic perovskite powder, and bismuth vanadate (BiVO₄). Both materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The morphology of the BiVO₄/CaBi₂Ta₂O₉/FTO platform was evaluated using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The photoelectrochemical response of the platform was evaluated by exploiting with light from a 36 W LED lamp confined in a low-cost homemade box. The BiVO₄/CaBi₂Ta₂O₉/FTO sensor showed superior photocurrent response compared to the FTO modified by the individual components (BiVO₄/FTO and CaBi₂Ta₂O₉/FTO). Under optimized experimental conditions, the photoelectrochemical sensor showed two linear ranges for PL concentrations ranging from 1 up to 900 μmol L^-1 and from 900 up to 2000 μmol L^-1, respectively.  The BiVO₄/CaBi₂Ta₂O₉/FTO sensor exhibited excellent results regarding precision, accuracy, and selectivity for PL detection. PL determination was successfully performed in water and artificial urine samples, with recovery values between 100.1 and 102.2%.