Continuous Determination of Glucose Using a Membraneless, Microfluidic Enzymatic Biofuel Cell.

Haroon Khan,Asad Ullah,Young Ho Kim,Jin Ho Choi,Gyu Man Kim

doi:10.3390/mi11121129

Abstract

In this article, we describe an enzyme-based, membraneless, microfluidic biofuel cell for the continuous determination of glucose using electrochemical power generation as a transducing signal. Enzymes were immobilized on multi-walled carbon nanotube (MWCNT) electrodes placed parallel to the co-laminar flow in a Y-shaped microchannel. The microchannel was produced with polydimethylsiloxane (PDMS) using soft lithography, while the MWCNT electrodes were replicated via a PDMS stencil on indium tin oxide (ITO) glass. Moreover, the electrodes were modified with glucose oxidase and laccase by direct covalent bonding. The device was studied at different MWCNT deposition amounts and electrolyte flow rates to achieve optimum settings. The experimental results demonstrated that glucose could be determined linearly up to a concentration of 4 mM at a sensitivity of 31 mV∙mM−1cm−2.

Highlights

Enzyme-based electrochemical biosensors, which use enzymes for signal transduction, have been extensively studied due to their high specificity and sensitivity toward their target analyte [1,2]
This work has demonstrated the feasibility of using membraneless, microfluidic biofuel cells, which were previously fabricated by our group for the electrochemical determination of glucose
The enzymes used as bio-recognition elements were covalently attached to multi-walled carbon nanotube (MWCNT) through modification with ethyl-N’(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC)/NHS

Summary

Introduction

Enzyme-based electrochemical biosensors, which use enzymes for signal transduction, have been extensively studied due to their high specificity and sensitivity toward their target analyte [1,2]. Ever since the first demonstration of an enzymatic glucose sensor in the early 1960s, research interest has grown considerably, thereby achieving many advancements in the field of biosensors [5] This progress has been reported in terms of the use of advanced materials, electrode design, enzyme immobilization strategies, analytical measurement methods, miniaturization techniques, etc. To get a high specific surface area, antifouling properties, and high conductivity, carbon nanotubes (CNTs) provide a versatile tool to construct bioelectrodes for electrochemical applications. Due to their high three-dimensional electroactive area that increases the surface concentration of both the enzymes and the redox mediators, CNTs have been the choice of scientists to utilize in enzymatic biofuel cells (EBFCs) [6]

Methods

Results

Conclusion