Non-Functionalized Graphene as an Electrical Sensing Surface for Bacterial Detection

Early detection of bacteria in food products is crucial for protecting human health and reducing economic losses. Althoughconventional methods, such as culture-based techniques, nucleic acid sequence-based detection, and immunoassays, are generallyaccurate, they are often time-consuming, labor-intensive, and require specialized equipment. In response to these limitations,sensing technologies emerge as simple, rapid, and cost-effective alternatives. Among these technologies, graphene gains significantattention due to its unique electrical properties and biocompatibility, making it a promising material for bacterial detection. Whilemost efforts focus on functionalizing sensors for specific targets, recent studies demonstrate that non-functionalized graphene caneffectively detect bacteria, enabling simpler and more affordable sensor design. This review provides a comprehensive analysisof non-functionalized electrical graphene-based bacterial sensors developed thus far. It evaluates and discusses the influence ofgraphene properties, bacterial activity, sensor design, and operational conditions on sensor performance. Additionally, the reviewemphasizes the need for further research to improve the reproducibility and scalability of reliable sensors and to develop sensitive,selective, and physiochemically stable devices.