Reusable Dual-Photopolymerized Holographic Glucose Sensors

Abstract

Diabetes is well established as a widespread, incurable, and fatal disease with glucose monitoring and tight glycaemic control vital for effective illness prevention and management. Hydrogel-based holographic sensors serve as a low-cost and label-free colorimetric sensing platform, directly identifiable by the naked eye and spectroscopy for quantitative monitoring. Herein, a cost-effective and reusable holographic glucose sensor is developed via single pulse UV-induced dual-photopolymerization of boronic acid functionalized hydrogels for point-of-care (POC) diagnosis. Computational modeling of holographic sensors response is conducted following Braggs law alongside the study of fabrication parameter optimization and sensor swelling dynamics. Fabrication conditions, responsive and interference hydrogel compositions of holographic sensors are investigated to improve response time, sensitivity in urine (13.03 nm mmol−1 L−1), limit of detection (0.06 mmol L−1), and reusability. Photolithographic patterning of hydrogel-based holographic sensors permits the inscription of additional information into the sensors for qualitative measurement. Selectivity, reversibility, and continuous monitoring of urine samples are conducted over a physiological glucose concentration range (0.0–9.4 mmol L−1) to demonstrate the viability for diabetic risk identification. The simple incorporation of glucose sensors in a reusable urinary analysis prototype is validated in human urine, showing potential for POC to reduce patient dependency on invasive diabetic monitoring procedures.