Date of Award

Spring 2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Program/Concentration

Biomedical Engineering

Committee Director

Gymama Slaughter

Committee Member

Michel Audette

Committee Member

Barbara Hargrave

Committee Member

Nancy Xu

Abstract

Lactate is a critical biomarker linked to conditions such as sepsis, ischemia, cancer, and heart failure. Current lactate detection methods remain invasive, costly, and unsuitable for real-time, continuous monitoring. This study presents the development of a flexible, non-enzymatic electrochemical biosensor based on laser-induced graphene (LIG) electrodes modified with gold nanoparticles (AuNPs) and molecularly imprinted polymers (MIPs) for highly selective and sensitive lactate measurement. The integration of AuNPs enhanced surface conductivity and provided nanoscale heterogeneity, facilitating superior signal amplification. The optimized LIG/AuNP/MIP sensor achieved an extensive dynamic detection range from 0.1 μM to 1000 μM, with an outstanding detection limit of 0.033 μM and a strong linear correlation (R² = 0.9556). The biosensor exhibited excellent selectivity against common interferents such as glucose, uric acid, ascorbic acid, and potassium ions. Stability studies demonstrated robust performance after prolonged storage at 4 °C, with regeneration enabled via CTAB treatment. Validation using artificial saliva yielded recovery rates between 102% and 113%, confirming accuracy in complex biological matrices. Mechanical tests further confirmed exceptional flexibility, with ~98% signal retention after mechanical twisting, supporting its application in wearable technologies. Compared to conventional enzymatic and non-enzymatic platforms, the LIG/AuNP/MIP biosensor offers enhanced sensitivity, stability, and durability. These findings establish a strong foundation for the future development of integrated, non-invasive, continuous lactate monitoring devices suitable for athletic performance tracking, critical care diagnostics, and personalized health management.

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In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/tha0-yg82

ISBN

9798280750531

ORCID

0000-0002-2820-5513

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