A wearable biosensing platform for continuous monitoring of inflammatory and metabolic biomarkers for real‐time health tracking and personalized care

Wearable biosensors have the potential to revolutionize health monitoring, yet reliable, time-resolved hormone and cytokine tracking remains elusive. This study introduces a dual-framework approach to enable circadian and immune profiling through perspired sweat sensing. First, sweat-saliva thresholds were calibrated for cortisol, melatonin, interleukin-6 and tumor necrosis factor-alpha, achieving significant classification performance (Area Under the Curve >0.80) for physiologically relevant salivary benchmarks. Second, circadian rhythmicity of each biomarker was modeled using circaCompare, revealing distinct oscillatory patterns stratified by age, gender, and stress. Young adults exhibited robust melatonin-cortisol phase separation and rhythmic immune signals. Older participants showed dampened amplitudes, phase shifts, and inflammatory dominance. Notably, stress exposure induced earlier cortisol peaks (Δ ≈ 6.7 h), suppressed melatonin rhythms, and heightened immune amplitude variability-hallmarks of circadian misalignment. These findings establish sweat as a valid, real-time medium for capturing endocrine and immune cycles, with analytical tools capable of uncovering early physiological strain. This work lays a foundation for personalized chronobiological monitoring and stress-risk screening in naturalistic settings.