Date of Award

2026

Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy in Biomedical Engineering (PhD)

Administrative Home Department

Department of Biomedical Engineering

Advisor 1

Smitha Rao

Advisor 2

Yixin Liu

Committee Member 1

Adrienne Minerick

Committee Member 2

Bruce Lee

Committee Member 3

Orhan Soykan

Abstract

Continuous glucose monitoring transforms care and performance, yet enzyme-based systems can drift and are sensitive to environmental variation in temperature, oxygen, and hydration. Non-enzymatic sensing with transition metal hydroxides promises greater stability and lower cost, but three barriers limit translation. First, catalytic surfaces such as Ni/Ni(OH)₂ are not inherently selective in complex matrices. Second, device-to-device variability can obscure true sensitivity gains at scale. Third, the redox activation of Ni(OH)₂ to NiOOH typically requires alkaline bulk media, while sweat is near neutral pH.

This dissertation addresses these barriers with a three-part program that links interfacial chemistry, platform engineering, and local microenvironment control. Aim 1 develops a selective non-enzymatic glucose sensor by coupling a glucose-imprinted polymer to an in-situ formed Ni/Ni(OH)₂ catalyst. The molecularly imprinted layer introduces target-preferential transport and binding at the electrode interface while preserving access to catalytic sites, which enables selective glucose oxidation in buffered and physiological samples. Aim 2 improves sensitivity and demonstrates reproducibility by adopting laser-induced graphene as a shared transduction substrate. A standardized LIG workflow produces conductive, porous electrodes that host both catalytic and affinity stacks with consistent signal quality across devices and batches. Aim 3 overcomes the need for bulk alkalinity through a dual-interdigitated LIG architecture that generates hydroxide ions in situ at a neighboring pad via the hydrogen evolution reaction. This local chemical control activates NiOOH at the sensing pad despite neutral bulk pH, enabling reliable non-enzymatic glucose measurements within the physiological sweat range of approximately 50 to 500 micromolar.

Together, these results establish a selective chemistry, a reproducible and sensitive platform, and a neutral-pH activation strategy that, in combination, close key gaps between laboratory demonstrations and real-world wearable operation. The approach provides a general pathway for molecular monitoring on flexible substrates and lays the groundwork for multi-analyte sensing in complex, variable environments.

Download

Available for download on Friday, July 09, 2027

Share

COinS