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

- A novel device based on CdSe/ZnS core-shell quantum dots sensitized with LiTCNE was developed.
- The photoelectroanalytical sensor exhibited photocurrent under visible LED light.
- Photoelectroanalytical sensor was applied for TBHQ determination in edible oils.

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 250 μmol L−1, sensitivity of 0.012 μA L μmol−1, and a limit of detection of 0.21 μmol L−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.