Ensuring access to safe water and public health necessitates sensitive, quick, and dependable detection instruments. Conventional techniques frequently have prolonged detection durations, intricate processes, and the requirement for skilled staff. Biosensors augmented with nanomaterials provide enhanced sensitivity, specificity, and rapid detection of waterborne pathogens. This review rigorously examines current developments in paper-based nano-biosensors, emphasizing their detection ranges, limits of detection, and fundamental principles. It underscores the pivotal function of nanomaterials in augmenting biosensor efficacy, especially in terms of sensitivity, selectivity, and longevity. Different biosensor technologies are analyzed, highlighting their specific benefits and drawbacks in the detection of waterborne illnesses. The paper examines the significant obstacles in converting proof-of-concept biosensors into commercial devices, such as durability, cost-efficiency, and scalability. Proposed solutions strive to surmount these obstacles, seeking to connect laboratory advancements with practical applications. This work offers significant insights for researchers, professionals, and policymakers engaged in water quality monitoring. It underscores the necessity for more research to enhance biosensor technologies, mitigate current limits, and expedite the production of effective, market-ready biosensors for the protection of public health via dependable detection of waterborne pathogens.