Selective and sensitive determination of phenolic compounds using carbon screen printing electrodes modified with reduced graphene oxide and silver nanoparticles

Butylated hydroxyanisole (BHA) and vanillin (VA) are the well-known phenolic compounds often used as preservatives in various foods and beverages. BHA is a safe additive whose concentration in food should not exceed 0.02 %. VA is used as a flavoring agent in foods, but the maximum allowable amount for VA is limited to 7 mg/ 100 g. However, elevated levels of BHA and VA can lead to severe health issues in the human body. To ensure reliable quality control, the food industry must accurately determine the BHA and VA content in food. In this work, we developed an electrochemical sensor for the detection of BHA and VA using a screen-printed electrode (SPE) modified with reduced graphene oxide and silver nanoparticles (RGO-Ag NPs). The SPE modified with RGO-Ag NPs showed an oxidation potential for BHA of 0.34 V and 0.62 V for VA in phosphate buffer solution (0.1 M PBS, pH 7.4) at a scan rate of 50 mV/s. In contrast, the unmodified SPE shows no significant current and oxidation potential response of BHA and VA under the same experimental conditions. (Cyclic voltammetry (CV) measurements for BHA ranged from 9.9 mu M to 239.25 mu M, while differential pulse voltammetry (DPV) measurements of BHA provided a linear calibration from 0.49 mu M to 3.67 mu M with a lower detection limit of 0.16 mu M (S/N = 3). For VA, CV measurements covered a range from 82.6 mu M to 242.4 mu M, and DPV measurements displayed a linear calibration from 1.47 mu M to 12.79 mu M with a detection limit of 0.15 mu M (S/N = 3).