Personalized assessment and monitoring of bone health from sweat: unveiling TEGO doped wearable, non-invasive hydrogel nanocomposite biosensor empowered by IL-6 detection.

Portable biosensing is crucial for rapid detection and continuous monitoring of bone diseases such as osteoporosis and bone cancer. It is well established that such bone disorders or diseases trigger release of inflammatory cytokines including interleukin-6 (IL6), detectable in sweat by electrochemical immunosensors. To this end, this study presents a novel hydrogel nanocomposite based immunosensor with highly conductive dual-layer of thermally exfoliated graphene oxide, toward precise detection and determination of loading level of IL-6 biomarker, and in turn, developing a label-free flexible bone biosensing platform. The immunosensor employed antibody immobilization process, which was further facilitated by the modification of the dual-layer by using 1-pyrenebutyric acid N-hydroxy succinimide ester. A thorough analysis of the effects of surface modification was conducted utilizing spectroscopic, electrochemical, and morphological methods. The biosensor's response was assessed through the utilization of the cyclic voltammetry measurement, which exhibited remarkable selectivity, achieving a low limit of detection of 15.4 pg ml^-1across a wide linear range. Additionally, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy were successfully used to validate the sensing substrate in bio-fluidic samples and to understand the structure-property correlation. This innovative portable and flexible biosensor thus offers a practical and effective tool for potential application in continuous monitoring of bone health.