UC San Diego

With the continuous growth in the field of glucose monitoring devices, non-invasive (NI)glucose monitoring devices integrating electrochemical glucose biosensors represent an attractive alternative to replace the gold standard self-monitoring of blood glucose (SMBG) or minimally invasive (MI) procedures. Current SMBG devices rely upon repetitive finger pricking to collect blood samples to quantify glucose levels, leading to discomfort from patients that require blood analysis, while MI procedures make use of skin penetrating approaches to collect glucose from an alternative biofluid. NI devices offer the unique capability of quantifying glucose levels without the need of penetrating the skin tissue to collect the sample. In this dissertation, the NI monitoring of glucose will be demonstrated in three different wearable sensing platforms using iontophoresis as a NI biofluid collection method coupled with electrochemical glucose sensing. The first platform delivered sweat-stimulating agents through the skin of volunteers using iontophoresis to enable sweat secretion. Sweat samples were then collected by a microfluidic platform that integrated a glucose biosensor. In the second platform, an adhesive patch that coupled an iontophoretic system and a glucose biosensor enabled glucose monitoring from the interstitial fluid for up to 8 and 4 hrs on healthy individuals and diabetic subjects respectively. In the last platform, the capability of performing glucose monitoring alongside multiple biomarkers of interest such as blood pressure, lactate, caffeine, and alcohol was demonstrated through different daily activities that involved exercise, food, and alcohol intake. Before human evaluation, each sensing modality was tested in terms of its sensing capability, stability, and selectivity toward the specific analyte of interest. During on-body operation, the results obtained from each sensing modality were validated by using commercial gold standard devices. Further data analysis implies the potential application of such devices as the next- generation NI platforms toward point-of-care operation.