Processable enzyme-hybrid conductive polymer composites for electrochemical biosensing

Publication date: 15 February 2018
Source:Biosensors and Bioelectronics, Volume 100
Author(s): Yu Liu, Anthony P.F. Turner, Maojun Zhao, Wing Cheung Mak
A new approach for the facile fabrication of electrochemical biosensors using a biohybrid conducting polymer was demonstrated using glucose oxidase (GOx) and poly (3, 4-ethylenedioxythiophene) (PEDOT) as a model. The biohybrid conducting polymer was prepared based on a template-assisted chemical polymerisation leading to the formation of PEDOT microspheres (PEDOT-MSs), followed by in-situ deposition of platinum nanoparticles (PtNPs) and electrostatic immobilisation of glucose oxidase (GOx) to form water processable GOx-PtNPs-PEDOT-MSs. The morphology, chemical composition and electrochemical performance of the GOx-PtNPs-PEDOT-MS-based glucose biosensor were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Fourier transform infrared (FTIR) spectroscopy, zeta potential and electrochemical measurements, respectively. The biosensor delivered a linear response for glucose over the range 0.1–10mM (R² = 0.9855) with a sensitivity of 116.25µAmM⁻¹cm⁻², and limit of detection of 1.55µM (3×SD/sensitivity). The sensitivity of the developed PEDOT-MS based biosensor is significantly higher (2.7 times) than the best reported PEDOT-based glucose biosensor in the literature. The apparent Michaelis–Menten constant (Km^app) of the GOx-PtNPs-PEDOT-MS-based biosensors was calculated as 7.3mM. Moreover, the biosensor exhibited good storage stability, retaining 97% of its sensitivity after 12 days storage. This new bio-hybrid conducting polymer combines the advantages of micro-structured morphology, compatibility with large-scale manufacturing processes, and intrinsic biocatalytic activity and conductivity, thus demonstrating its potential as a convenient material for printed bioelectronics and sensors.



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