The detection of uric acid, urea, and creatinine—key biomarkers for renal and metabolic disorders—has significantly advanced with the development of nanomaterial-based biosensors. This chapter presents a comprehensive review of recent progress in electrochemical and optical sensing platforms that leverage the unique physicochemical properties of nanomaterials such as metallic nanoparticles, metal oxide nanostructures, carbon-based materials, and polymeric nanocomposites. These materials enhance biosensor performance by increasing electron transfer efficiency, catalytic activity, and surface functionalization, thereby improving sensitivity, selectivity, and stability. Enzyme-based and non-enzymatic detection strategies are discussed, alongside emerging applications in flexible, wearable, and smartphone-integrated devices. Special emphasis is placed on molecularly imprinted polymers, metal-organic frameworks, and hybrid nanocomposites as next-generation platforms for point-of-care diagnostics. The chapter also explores challenges related to biocompatibility, scalability, and regulatory compliance, and outlines future directions including the use of MXenes, AI integration, and biodegradable sensors. These innovations collectively position nanomaterial-enabled biosensing as a transformative approach for real-time, personalized healthcare monitoring.