Analytical Parameters of a Novel Glucose Biosensor Based on Grafted PFM as a Covalent Immobilization Technique.

Margalida Artigues,Robert Texidó,Salvador Borrós,Sergi Colominas,Joan Gilabert-Porres,Jordi Abellà

doi:10.3390/s21124185

Abstract

Bioanalytical methods, in particular electrochemical biosensors, are increasingly used in different industrial sectors due to their simplicity, low cost, and fast response. However, to be able to reliably use this type of device, it is necessary to undertake in-depth evaluation of their fundamental analytical parameters. In this work, analytical parameters of an amperometric biosensor based on covalent immobilization of glucose oxidase (GOx) were evaluated. GOx was immobilized using plasma-grafted pentafluorophenyl methacrylate (pgPFM) as an anchor onto a tailored HEMA-co-EGDA hydrogel that coats a titanium dioxide nanotubes array (TiO2NTAs). Finally, chitosan was used to protect the enzyme molecules. The biosensor offered outstanding analytical parameters: repeatability (RSD = 1.7%), reproducibility (RSD = 1.3%), accuracy (deviation = 4.8%), and robustness (RSD = 2.4%). In addition, the Ti/TiO2NTAs/ppHEMA-co-EGDA/pgPFM/GOx/Chitosan biosensor showed good long-term stability; after 20 days, it retained 89% of its initial sensitivity. Finally, glucose concentrations of different food samples were measured and compared using an official standard method (HPLC). Deviation was lower than 10% in all measured samples. Therefore, the developed biosensor can be considered to be a reliable analytical tool for quantification measurements.

Highlights

Titanium (99.7%), glucose oxidase (GOx) type VII from Aspergillus niger, low molecular weight chitosan, and hydroxyethyl methacrylate (HEMA) were all supplied by Sigma Aldrich
Pentafluorophenyl methacrylate (PFM) was supplied by Apollo Scientific, and Argon 5.0 was supplied by Carburos Metaálicos
The immobilized enzyme molecules on the biosensor showed a strong ability of substrate binding and high enzymatic activity, as indicated by the KM app value of 3.44 ± 0.67 mM. Measurements undertaken with this biosensor showed high accuracy, with a deviation from HPLC

Summary

Introduction

Biosensors and related bioanalytical tools are increasingly used as complements for standard analytical methods in a large number of applications, such as environmental monitoring [1,2,3], clinical diagnostic [4,5,6], and food analysis [7,8,9]. These devices offer fast and cost-effective measurements that can be made in situ, and are able to provide real-time measurements. The combination of new communication technologies, such as smartphones and tablets, with these bioanalytical devices allow the development and acquisition of easy-to-use devices and easy-to-read measurements [14,15]

Methods

Results

Conclusion