Biosensors for detecting communicable and non-communicable diseases: A critical review

Biosensors have become crucial analytical tools in modern medicine, attracting scientists' attention. They offer rapid, sensitive, and cost-effective detection of disease biomarkers. This review provides a critical overview and summarizes biosensor components and transduction modes, evolution, and clinical applications, with a focus on communicable and non-communicable diseases. The progression from early enzyme electrodes to nanomaterial-enabled electrochemical and optical platforms, alongside microfluidic and wearable formats, has expanded capabilities for point-of-care testing and longitudinal data acquisition. Clinically approved biosensors, such as those for glucose, cardiac troponins, and prostate-specific antigen illustrate that the translation of biosensor research into practical healthcare solutions is feasible under appropriate regulations and holds a promise for the future to come. Recent developments in electrochemical, microfluidic, and Surface Plasmon Resonance (SPR)-based sensing support multiplexed and miniaturized systems aimed at point-of-care testing and, in some cases, continuous monitoring. By presenting FDA-cleared and CE-marked platforms, specifically for NCDs, and comparing them with clinically approved CD assays, we highlight a persistent translational gap. Despite existing challenges in sensor stability, matrix effect, biofouling, calibration, manufacturability, and large-scale clinical validation, the integration of biosensors with nanotechnology, artificial intelligence, and wireless communication holds promise for the next generation of personalized, decentralized healthcare. We also discuss how the use of AI/ML for longitudinal signals, sustainable design, and alignment with One Health perspective collectively shape translation from lab-ready sensors to clinically adopted systems. Overall, biosensors represent a powerful convergence of biology and engineering that is reshaping diagnostic medicine and enabling more accessible, real-time, and patient-centered health management.