Development of a photoelectrochemical sensor for detection of TBHQ antioxidant based on LiTCNE-TiO2 composite under visible LED light

In this work, a novel photoelectrochemical sensor for detection of tert-butylhydroquinone (TBHQ) based on anatase titanium dioxide (TiO2) nanoparticles sensitized with lithium tetracyanoethylenide (LiTCNE/TiO2) was developed. The LiTCNE/TiO2 photoelectrochemical sensor showed high anodic photocurrent to TBHQ under visible LED light irradiation in comparison to pure anatase TiO2 nanoparticles or pure LiTCNE. The LiTCNE/TiO2 composite shows a photocurrent to TBHQ about 28 times higher than that observed to TiO2 nanoparticles and 4-fold higher than that observed to LiTCNE modified electrode. The LiTCNE/TiO2 composite showed a low charge transfer resistance in comparison to their individual components. Under optimized conditions, the photoelectrochemical sensor shows a linear response range from 0.4 up to 500 μmol L− 1 with a sensitivity of 0.01 μA L μmol− 1 and limit of detection of 100 nmol L− 1 for the detection of TBHQ. The photoelectrochemical sensor showed high photocurrent to TBHQ in comparison to photocurrent response to butylated hydroxyanisole (BHA) and butyl-hydroxytoluene (BHT). The present LiTCNE/TiO2 photoelectrochemical sensor was successfully applied to biodiesel samples, with recovery values between 96.8% and 98.2%. The results obtained were found to be similar to those obtained using the spectrophotometric method with agreement at 95% confidence level.