Biomarkers in wearables, ingestible, and implantable sensors for health monitoring.

Biomarkers are vital indicators of biological processes and play a key role in diagnostics and personalized medicine. This chapter discusses the classification of biomarkers and presents an overview of biosensing technologies developed for their detection through wearable, ingestible, and implantable sensor platforms. Wearable sensors mainly track physiological signals, such as heart rate and temperature, and are increasingly capable of detecting biochemical markers in sweat or interstitial fluid. Ingestible sensors provide non-invasive access to the gastrointestinal tract, detecting biomarkers like pH, gases, and metabolites to assess systemic health. Implantable sensors, integrated into body tissues, enable long-term, high-resolution monitoring of internal biomarkers. The future of biosensing lies in multi-modal platforms that combine various sensing technologies with AI-driven data analysis to enhance diagnostic precision and support personalized treatments. However, despite significant advancements, several challenges remain, including ensuring sensor biocompatibility, managing power requirements, securing health data, navigating regulatory approvals, and addressing ethical concerns. Overcoming these barriers is essential for successful clinical translation and broader commercialization.