Highly sensitive and label-free electrochemical sensor for menthol detection

Abstract

Menthol is a monocyclic monoterpenoid alcoholic compound and generally used in foods as additive and in medicine as analgesic and antipruritic. Poor water solubility and high volatility of menthol limit its application and increase the difficulty of detection. Herein, we proposed a simple and label-free method to sensitively detect menthol using differential pulse voltammetry (DPV). To improve the detection sensitivity, silica microspheres (SiO2) were introduced for better modification and enrichment of ferrocene (Fc) on the electrode surface. Based on the inclusion action of Fc and β-cyclodextrins (β-CD), the electrochemical signal of Fc was inhibited due to the limitation of Fc oxidation by β-CD cavity. However, when menthol presented, the electrochemical signal of Fc has a remarkable recovery. The recovered electrochemical signal increased with the increasing concentration of menthol, and showed a good linear relationship. Thus, the proposed electrochemical sensor is available for quantitative detection of menthol with high sensitivity.