A simple and sensitive method for the determination of propranolol using a modified carbon paste electrode (CPE) with graphene/Co3O4 nanocomposite (Gr-Co3O4 NC/CPE) was presented. The electrochemical measurements of propranolol are studied using differential pulse voltammetry (DPV), cyclic voltammetry (CV) and chronoamperometry (CHA). The Gr-Co3O4 NC/CPE exhibits excellent catalytic activity towards the electrochemical oxidation of propranolol in phosphate buffer solution (PBS) of pH 7.0. The Gr-Co3O4 NC/CPE facilitates the determination of propranolol in the concentration range 1.0–300.0 μM and a detection limit and sensitivity of 0.3 μM. and 0.1275 μA/μM were achieved.

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Amaranth dye is an organic compound largely used in the food and beverage industries with potential toxicity effects on humans. In this paper, a new electrochemical sensor used for the determination of amaranth in foods was reported, where a kind of V2O5 nanoplate (V2O5-NPs) was employed as electrode modifying materials. The V2O5 nanoplate modified electrode enhanced its electrochemical signal obviously in the determination of amaranth in foods and exhibited a wider linear response ranging from 0.1-270.0 µM with a low detection limit of 0.04 ± 0.001 µM (3Sb/m). This work offers a new route in developing new electrochemical sensors for the determination of colorant additives and other hazardous components in foods.