The determination of skin surface pH via the skin volatile emission using wearable colorimetric sensors

Biodiagnostic sensors in the form of wearables have become widespread interest both scientific and clinical communities recent years due to their potential for monitoring human health, well-being physical performance. However, collecting biofluids from skin enable biochemical analysis using has proved challenging date. This research seeks overcome need fluid collection by designing a wearable sensing platform capable volatile emission with aim biodiagnostic information body. We investigate use simple colorimetric incorporating sensor spots comprising encapsulated bromocresol green pH indicator dye an enclosed headspace above skin. The undergo colour change response basic nitrogen compounds such as ammonia amines being emitted By deploying this healthy participant study, strong correlation between surface was demonstrated, despite significant inter-individual variability noted. Sensor observed be highly dependent on gender well body site, attributed factors gland microbial composition differences. Finally, wearable's ability detect changes topical treatments demonstrated. Overall, work demonstrates novel approach biodiagnostics that exploits monitor physiology without microneedles or requirement harvest