Ratiometric electrochemical sensor based on polythionine/multiwalled carbon nanotube composite for butylated hydroxyanisole determination

Abstract

A ratiometric electrochemical sensor is developed for fast, simple and accurate determination of BHA using polythionine/multiwalled carbon nanotube composite modified glassy carbon electrode (pThi/MWCNT/GCE). The preparation of pThi/MWCNT/GCE is characterized by various analytical techniques. The pThi/MWCNT composite is demonstrated to possess large specific surface area, good electrical conductivity, and high electrocatalytic ability. Moreover, it is demonstrated that the use of ratiometric signal involving the electro-oxidation of both BHA and pThi improves the accuracy and reliability of the BHA analysis due to the built-in correction function of the inner reference polythionine probe. A linear ratiometric signal can be achieved over the concentration range of 0.5–70.0 μM with the detection limit of 0.21 μM (S/N = 3). The BHA sensor also exhibits high selectivity, high reproducibility, and good stability, and can be used for the analysis of BHA in edible oil samples with satisfactory results.