Biofriendly and Regenerable Emotional Monitor from Interfacial Ultrathin 2D PDA/AuNPs Crosslinking Film

Well-designed 2D materials with ultrathin structures show great potential for humidity sensing performance owing to their high surface-volume ratio and a great number of exposed atoms on the surface. However, some sensing elements employed for healthcare applications may be considered as potentially risky, such as inflammation, granuloma formation, and carcinogenesis. Herein, we explored a biofriendly humidity sensing characteristics inspired by the great biocompatibility and conductivity of hyperbranched polyethyleneimine (HPEI)-capped gold nanoparticles (AuNPs) and crosslinked with polydopamine (PDA) from the adhesive proteins in mussels. It was successfully employed into two kinds of wearable devices, sports watches and breathing masks, for real-time recording humidity’s fluctuation in expiration and sweat with changes of individual’s crying, laughing, nervous, sleeping, training and cold states. The wearable devices allow monitoring individual’s physical activities and emotional states well, suggesting promising prospect in the safe, reusable, long term and noncontact human health monitoring applications.