Glucose biosensor based on functionalized ZnO nanowire/graphite films dispersed on a Pt electrode

Abstract

We present a glucose biosensor based on ZnO nanowire self-sustained films grown on compacted graphite flakes by the vapor transport method. Nanowire/graphite films were fragmented in water, filtered to form a colloidal suspension, subsequently functionalized with glucose oxidase and finally transferred to a metal electrode (Pt). The obtained devices were evaluated using scanning electron microscopy, energy-dispersive x-ray spectroscopy, cyclic voltammetry and chronoamperometry. The electrochemical responses of the devices were determined in buffer solutions with successive glucose aggregates using a tripolar electrode system. The nanostructured biosensors showed excellent analytical performance, with linear response to glucose concentrations, high sensitivity of up to ≈17 μA cm(-2) mM(-1) in the 0.03-1.52 mM glucose concentration range, relatively low Michaelis-Menten constant, excellent reproducibility and a fast response. The detection limits are more than an order of magnitude lower than those achievable in commercial biosensors for glucose control, which is promising for the development of glucose monitoring methods that do not require blood extraction from potentially diabetic patients. The strong detection enhancements provided by the functionalized nanostructures are much larger than the electrode surface-area increase and are discussed in terms of the physical and chemical mechanisms involved in the detection and transduction processes.

Glucose Oxidase/Nano-ZnO/Thin Film Deposit FTO as an Innovative Clinical Transducer: A Sensitive Glucose Biosensor

“…Table 2 compares the analytical characteristics of the GOx/nano-ZnO/PVA/FTO biosensor with other reported glucose biosensors. The biosensor in the present work clearly shows better analytical factors, such as the detection limit and response time, than previously reported sensors (Wei et al, 2010 ; Marie et al, 2015 ; Gallay et al, 2016 ; Mandal et al, 2016 ; Asrami et al, 2018 ; Nguyen et al, 2019 ; Sabu et al, 2019 ). This advantage is relative to covalent enzyme immobilization in our fabricated biosensor.…”

“…There are many medical research reports on enzymatic glucose measurements based on the best-nanostructured metal oxide textures and composites (Karimi-Maleh et al, 2019c ). Some nanostructured metal oxides such as zinc oxide (ZnO) have been studied in recent years owing to their strong ability to facilitate electron transfer between the electrode and the surface active site (Aini et al, 2015 ; Baghizadeh et al, 2015 ; Gallay et al, 2016 ; Zhao et al, 2016 ; Chung et al, 2017 ; Israr-Qadir et al, 2017 ; Moghaddam, 2017 ; Zhou et al, 2017 ; Karimi-Maleh et al, 2019a , c ; Miraki et al, 2019 ; Shamsadin-Azad et al, 2019 ; Karimi-Maleh and Arotiba, 2020 ). The application of nanomaterials, especially nanoparticles, in various industries and technologies, and especially in the design of electrochemical sensors, has been well-studied (Rayati and Malekmohammadi, 2016 ; Dehhaghi et al, 2019 ; Hassandoost et al, 2019 ; Hosseini et al, 2019 ; Karimi-Maleh et al, 2019b , 2020a , b , c ; Malekmohammadi et al, 2019 ).…”

Metal oxide nanostructures for sensor applications

“…Several reports have demonstrated the application of ZnO as biosensors, i.e. in DNA immobilization [180], in glucose level detection [176,177,181], for cardiac biomarker detection [179,182,183] and also for cancer diagnostic [178,184,185].…”

“…Probably the application of ZnO for glucose detection is one of the most studied biosensors. For glucose levels detection , ZnO biosensors are produced by immobilization of glucose oxidase enzyme onto ZnO nanostructures [176]. The high IEPZnO value will promote the formation of zinc oxide/ glucose oxidase complexes during functionalization (glucose oxidase are negatively charged molecules, that will be readily attracted and immobilized onto positively charged zinc oxide).…”

“…Gallay et al [176] was able to produce a ZnO nanowire-based glucose sensor capable of detecting very low glucose concentrations of about 9 M. Wahab et al [181] used ZnO nanorods for the detection of glucose with concentration ranging from 1 M to 10 mM.…”