Photoelectrochemical determination of tert-butylhydroquinone in edible oil samples employing CdSe/ZnS quantum dots and LiTCNE

Abstract

A novel photoelectrochemical sensor was developed for determination of tert-butyl-hydroquinone (TBHQ) in edible vegetable oils, based on CdSe/ZnS core-shell quantum dots sensitized with lithium tetracyanoethylenide (LiTCNE). The CdSe/ZnS/LiTCNE photoelectrochemical sensor presented a TBHQ photocurrent about 13-fold higher and a charge transfer resistance 62-fold lower than observed for a CdSe/ZnS sensor. The photoelectrochemical sensor showed selectivity to TBHQ, with a high photocurrent for this antioxidant compared to the photocurrent responses for other phenolic antioxidants. The CdSe/ZnS/LiTCNE photoelectrochemical sensor presented a linear range from 0.6 to 250μmolL^-1, sensitivity of 0.012μALμmol^-1, and a limit of detection of 0.21μmolL^-1 for TBHQ, under optimized experimental conditions. The sensor was successfully employed in the analysis of edible oil samples, with recoveries of between 98.25% and 99.83% achieved.

Keywords: CdSe/ZnS quantum dot; Edible oil; LiTCNE; Photoelectrochemical sensor; TBHQ detection.