Carbon-based nanocompositesNanocomposites haveCarbon-based nanocomposites emerged as transformative materials in sensing and biosensing technologies, leveraging their unique physicochemical properties to address critical challenges in medicalMedical screening and ecosystem monitoring. These nanocomposites, incorporating grapheneGraphene, carbon nanotubesCarbon Nanotube (CNT) (GQDs), graphene oxideGraphene Oxide (GO) (GO), and carbon quantum dots (CQDs), exhibit exceptional electrical conductivity, high surface-to-volume ratios, and biocompatibility, enabling precise biomolecule immobilization and signal transduction. Recent advancements highlight their integration into electrochemical and optical biosensors, where they enhance sensitivity, selectivity, and detection limits for biomarkers, pathogens, and metabolites. For instance, functionalized carbon nanotubes and grapheneGraphene oxide have been utilized in electrochemical platforms to achieve real-time monitoring of diseases like COVID-19, with detection limits as low as 1 pM for target analytes. Hybrid nanocompositesNanocomposites, combining carbon nanomaterialsCarbon Nanomaterials (CNM) with polymersPolymer or metallic nanoparticlesNanoparticles, further improve antifouling properties and signal amplification, addressing non-specific binding issues in complex biological matrices. Despite progress, challenges such as batch-to-batch reproducibility, long-term stability in vivo, and scalable fabrication remain barriers to clinical translation. Innovations in wearable sensors and point-of-care devices underscore their potential for decentralized diagnostics, particularly in diabetes management through continuous glucose monitoring. Future research directions emphasize ecofriendly synthesis, advanced functionalization techniques, and validation in real world to close the gap between experimental research and everyday application. By harnessing the synergistic effects ofCarbon nanocomposites carbon nanocompositesNanocomposites, next-generation biosensors are poised to revolutionize early disease detection and personalized health care.