An Injectable PEG-BSA-Coumarin-GOx Hydrogel for Fluorescence Turn-on Glucose Detection.
Appl Biochem Biotechnol 2015;
177:1115-26. [PMID:
26288081 DOI:
10.1007/s12010-015-1800-2]
[Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/02/2015] [Indexed: 10/23/2022]
Abstract
Diabetes mellitus is a chronic metabolic disorder, requiring vigilant monitoring of blood glucose levels. In this study, an injectable fluorescent enzymatic hydrogel was designed for rapid glucose detection. The leakage-free glucose-responsive hydrogel was constructed by the covalent linkage of a multi-arm poly-(ethylene glycol) (PEG), bovine serum albumin (BSA), glucose oxidase (GOx), and 4-(aminomethyl)-6,7-dimethoxycoumarin (Coumarin-NH2). The GOx serves as glucose-recognition element and the pH-sensitive Coumarin-NH2 as a fluorescence turn-on reporter. The material properties of the fluorescent hydrogel were systematically characterized which show high elasticity with good mechanical strength. Upon the addition of glucose, the as-developed fluorescent hydrogel shows a fast response time, good sensitivity, and good reproducibility at physiological pH and ambient temperature. The glucose-sensing mechanism is based on the oxidation of the glucose by GOx that generates protons to change the local pH. Consequently, protonation of the covalently immobilized and pH-sensitive Coumarin-NH2 turns on the fluorescence of the coumarin. The fluorescence hydrogel developed holds great promise as an injectable, implantable glucose-sensing biomaterials for in vivo continuous glucose monitoring.
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