Flexible and self-healing electrochemical hydrogel sensor with high efficiency toward glucose monitoring

Publication date: Available online 19 February 2020Source: Biosensors and BioelectronicsAuthor(s): Zhen Liang, Jieyu Zhang, Can Wu, Xuefeng Hu, Yuhui Lu, Guangfeng Wang, Fei Yu, Xiaojun Zhang, Yunbing WangAbstractThe commercial sensor of a continuous glucose monitoring system suffers from restricted penetration of glucose in the dense sensing coating, uncontrolled leakage of the glucose oxidase and electrocatalytic medium, and susceptibility to mechanical damage. Herein, a self-healing hydrogel based on quaternized chitosan and oxidized dextran was designed, and CeO2/MnO2 hollow nanospheres were covalently linked in the hydrogel as the electrocatalytic medium. Glucose oxidase was loaded via the strong electrostatic interactions with the CeO2/MnO2 hollow nanospheres. An extra covering agent was coated on the hydrogel to prevent the leakage of the glucose oxidase and electrocatalytic medium. Covalent linkage of the hydrogel on a bendable chip formed a flexible glucose sensor, which showed a wide linear range (1–111 mM), fast response (less than 3 s), and high sensitivity (176 μA mM−1 cm−2). The hydrogel-based sensor was self-healable, and could continuously work for over 30 days. Thus, this study provides a method to simultaneously prevent the leakage of the electrocatalytic medium, promote the sensitivity of glucose detection, and tolerate the mechanical damage, which shows great potential for continuous glucose monitoring.Graphical abstract

Source: Biosensors and Bioelectronics - February 19, 2020 Category: Biotechnology Source Type: research