A bio-mimicking cobalt tetramenthol-substituted phthalocyanine-based electrochemical sensor for selective and sensitive detection of tert-butylhydroquinone†

Abstract

Healthy eating choices and adequate nutritional foods are the most important factors in extending a person's life expectancy. Synthetic antioxidants are frequently used in the food industry as preservatives despite their toxicity and hence have drawn much attention for their accurate monitoring. This study explores the newly designed cobalt tetramenthol substituted phthalocyanine (CoTMPc) for the electrocatalytic detection of an artificial food preservative, i.e., tertiary butylhydroquinone (TBHQ). A highly selective, cost-effective electrochemical probe is developed for the nanomolar detection of TBHQ. Its efficacy is evaluated and validated by different electrochemical techniques, namely cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA) and the CA results demonstrated a good sensitivity of 1.3102 μA nM⁻¹ cm⁻² with a linear range of 20–200 nM and a detection limit (LOD) of 4.5 nM in comparison to other techniques. The developed sensor was successfully applied to real samples. The CoTMPc electrode exhibited superior sensitivity, excellent selectivity, repeatability, and reproducibility, with anti-interference ability, over a broad linear range towards TBHQ detection. The mechanism of electrochemical detection is supported by fluorescence resonance energy/electron transfer and provides insights into the design of high-performing electroactive molecules that induce specificity and selectivity.