Wearable sensors have become popular in recent years with many types being available on the commercial market. These wearable sensors allow the monitoring of physiological parameters such as heart rate but give limited insights into the body’s biochemistry and lack the ability to characterize important metabolic processes. While blood is the “gold standard” for monitoring the body’s biochemistry, it is known that various components of skin, including interstitial fluid (ISF) and sweat offer alternative, non-invasive “windows” into the health of the individual via the tracking of biomarkers present within these matrices. This has prompted the innovative development of new types of wearable biodiagnostic platforms capable of in- situ extraction and analysis of these various skin matrices. Wearable sensor development for biofluids such as ISF and sweat have thrown up many challenges with respect to generating and collecting sufficient volumes of such biofluids for reliable analyte detection. This thesis seeks to overcome the specific requirement for biofluid collection and manipulation by investigating the volatile emission from skin, a matrix that is continuously emitted from skin and which contains biomarkers of metabolic and cellular processes within the body. The work seeks to establish the volatile profile for healthy skin using a headspace solid-phase microextraction (HS-SPME) gas-chromatography (GC-MS) workflow to better understand factors that impact the emission including circadian rhythm, skin sampling site, gender and age. Mammalian cell culture studies were undertaken to investigate the response of human keratinocytes to frequently emitted skin volatiles to further understand and establish the contribution of such skin-derived compounds to the induction of cutaneous protective pathways. Finally, a move toward the use of a simple, cost-effective, wearable colorimetric sensor platform to monitor volatile emissions from skin was also explored with the feasibility of measuring skin surface pH, through the volatile ammonia emission from skin. Overall, this work seeks to understand the robustness of the healthy skin volatile profile across a population and to demonstrate novel, simple approaches to tracking volatiles of interest to health via HS-SPME GC-MS workflows and wearable colorimetric-based biodiagnostics while also outlining their challenges and limitations. Exploiting the skin volatile emission to monitor skin physiology without the need for microneedles or the requirement to harvest fluid from skin is enticing. The understanding of this emission and its exploitation for wearable biodiagnostics has great potential for personalised monitoring of general health and self-management of chronic diseases shown to be associated with volatile biomarkers in the future.