In the present study, an electrochemical-impedimetric biosensor using Saccharomyces cerevisiae as an effective biorecognition element was designed to detect caffeine. The presented biosensor consists of a previously developed stainless steel electrochemical cell constructed as a three-electrode system in the RCW side-by-side configuration. The electrochemical stability of the sensing electrode was evaluated by measuring the open circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) was applied to determine the impedimetric response of the biosensor with Saccharomyces cerevisiae cells attached to the working electrode (WE) in the absence (0.9% NaCl) and presence (10 mg/mL in 0.9% NaCl) of caffeine. Moreover, the limit of detection (LOD) was determined. In this way, a new approach in biosensor development has been established, which involves assembling a low-cost and disposable electrochemical system to detect alkaloids such as caffeine. The developed biosensor represents a good candidate for detecting caffeine in beverages, foods, and drugs with the merits of time-saving, robustness, low cost, and low detection limit.
Keywords: Impedimetric biosensor; Saccharomyces cerevisiae; caffeine; electrochemical impedance spectroscopy.