High‐Performance Flexible Bioelectrocatalysis Bioassay System Based on a Triphase Interface
Qingqing Cheng, Jun Zhang, Haili Wang, Dandan Wang, Xinjian Feng, Lei Jiang
Abstract
Abstract Flexible biosensor technologies are essential for the development of noninvasive bioassays such as those based on sweat or interstitial fluid analysis. Cathodic measurement of oxidase catalytic product H 2 O 2 is an ideal principle for analyte detection, with O 2 serving as an electron mediator. Herein, the authors report a flexible bioassay system comprising a flexible superhydrophobic polydimethylsiloxane micropillar array substrate, a noble metal H 2 O 2 electrocatalyst‐decorated carbon nanotube film, and an oxidase enzyme top layer. The flexible bioassay system possesses a solid–liquid–air triphase bioelectrocatalysis reaction interface where oxygen levels are air phase dependent, hence constant and sufficient, which enhances and stabilizes the oxidase kinetics. In comparison with conventional flexible diphase bioassay systems, when used for analyte detection including but are not limited to glucose, choline, and lactate in body fluids, the triphase bioassay system displays a wide linear dynamic range and high selectivity. Moreover, the flexible bioassay system remains intact and fully operational after being bent over 500 times. Such a system should greatly promote the development of noninvasive biosensors for the monitoring of physiological biomarkers.