Modular assembly of enzyme loaded nanoparticles in 3D hollow fiber electrode for electrochemical sensing
By Wu, Huimin; Zhang, Xinran; Wei, Chenjie; Wang, Chengcheng; Jiang, Min; Hong, Xiao; Xu, Zhikang; Chen, Dajing; Huang, Xiaojun
Published in Chemical Engineering Journal
2021
Abstract
We have developed a three-dimensional (3D) enzyme loading strategy by modular assembly of enzyme loaded nanoparticles with porous conductive membranes. A 3D conductive structure was fabricated as electrode via the poly-(3,4-ethylenedioxythiophene) (PEDOT) in-situ synthesized on hollow fiber membranes (HFMs) framework, retaining the original gradient porous structures and capillary effect. Using physical entrapment pattern, enzyme-carrying nanoparticles were modularly assembled in the 3D conductive support and their spatial distribution can be regulated by particle size-tuning. The obtained enzyme entrapped 3D composites can be applied as a promising electrode in electrochemical sensing and catalysis. HFMs provide large surface area and gradient porous structure for entrapping the enzyme-carrying nanoparticles in the confined micro-space. The physical entrapment improves the enzymatic stability and promotes full contact between the enzymes and the conductive/catalytic substrates. The conductive support creates an interconnected network to increase the electrode area and the response current, thus enhancing the sensitivity of biosensors. It shows fast current response (~3 s), wide linear range (glucose, 2–24 mM; lactic acid, 0.1–6 mM), high sensitivity, and low detection limit (glucose, 100 µM; lactic acid, 10 µM) towards cancer cell metabolism monitoring. This electrode structure can be further applied in multi-target array detection towards metabolic markers by modulating different enzymes on the conductive HFMs.