Caffeine Electrochemical Sensor Constructed by Graphene Oxide and Reduced Graphene Oxide: A Mini-review

It is very important to determine the concentration of target substances in food safety, environmental detection, and drug supervision. Caffeine, a natural alkaloid, is widely found in various drinks and drugs. In addition to its beneficial functions, caffeine also has certain negative effects. Therefore, it is very important to determine the concentration of caffeine in drugs, beverages, wastewater, and other media. Among various analytical techniques, electrochemical sensors occupy a special position because of their high efficiency, rapidity, and relative ease to obtain the required preparation and measurement conditions. In the past decades, great progress has been made in the determination of caffeine using graphene oxide (GO) and reduced graphene oxide (RGO) as electrochemical sensor materials. GO and RGO have the advantages of low preparation cost, significant dissolution in polar solvents, such as water, wide working potential range, and relatively high electrochemical inertia in various redox reactions. Moreover, due to π -π interaction and other reasons, their reactivity to caffeine is higher; therefore, GO and RGO applications in caffeine sensors are more popular, and good results have been obtained in selectivity and sensitivity. In this study, the related literature on caffeine in electrochemical sensors preparation with GO and RGO in recent years is reviewed, with the aim of helping researchers working in this research field.