Development of an electrochemical device based on aptasensors for the determination of caffeine in beverages

Herein, we constructed a miniature electrochemical device for highly sensitive and selective detection of caffeine in beverages. A disposable gold-film plastic electrode was modified with the caffeine-specific aptamer to serve on the working electrode. It was then equipped in a detachable three-electrode test system to perform the electrochemical measurements. The whole device is robust, cost-effective, easy to fabricate, and convenient to maintenance. The preparation of the proposed device was carefully characterized and optimized. Under optimal analytical conditions, the concentration of caffeine in the range of 0.1 − 50 nM showed a good linear relationship, and the detection limit was as low as 0.079 nM. The developed method also exhibited good stability and selectivity. The practicality of this device was certified by testing the caffeine concentration in beverages on the market and comparing the results with the method based on UPLC-HRMS.