Functionalized Graphene Oxide Bridging between Enzyme and Au-Sputtered Screen-Printed Interface for Glucose Detection

Abstract

This work reports the fabrication of an electrochemical glucose biosensor based on functionalized graphene, assembled onto a gold-sputtered screen-printed electrode. With the aim of simplicity, versatility, and low cost, biosensors dually functionalized with graphene oxide containing excess carboxylic acids and thiol functionality were synthesized and characterized by Fourier transform infrared, Raman, and UV–vis spectroscopy. The increased carboxylic groups of the graphene backbone provided more active sites for the remote functional groups of glucose oxidase during 1-ethyl-3-(3-(dimethylamino)­propyl)­carbodiimide-assisted immobilization. The modified electrode interface was characterized by scanning electron microscopy, atomic force microscopy, and cyclic voltammetry. This hybrid electrode interface showed higher sensitivity for glucose (3.1732 μA mM–1 cm–2) with a detection limit of 0.3194 mM (S/N = 3). Furthermore, the fabricated biosensor demonstrated a linear response in 3–9 mM glucose concentration with the correlation coefficient of 0.94693, a performance well beyond that of the similarly fabricated electrode interfaces in terms of selectivity and efficiency. The enhanced electrochemical performance is assumed to originate simultaneously from sputtered morphology of Au and the bifunctionality of the graphene backbone. This work highlights the significant potential for Au-sputtered electrode interfaces coupled with a bifunctional graphene backbone toward several biomedical applications.

Recent Trends in the Improvement of the Electrochemical Response of Screen-Printed Electrodes by Their Modification with Shaped Metal Nanoparticles

“…Other investigations have reported the use of this technique to modify the sensor’s surface [ 64 , 65 ]. The sputter coating is referred to the use of the energy of a partially ionized gas (usually argon) on the surface of a target (cathode) to pull out the atoms of the material one by one, and deposit them on the substrate [ 66 ].…”

Glucose Biosensor Based on Disposable Activated Carbon Electrodes Modified with Platinum Nanoparticles Electrodeposited on Poly(Azure A)

“…Only the biosensors published in the literature [ 23 , 38 , 41 ] showed a slightly higher sensitivity in the same order of magnitude. In addition, the GOx-PtNPs-PAA-aSPCE biosensor has a good linear range (from micromolar to millimolar) in contrast with other biosensors, such as those reported in the literature [ 45 , 46 ]. The limit of detection is also lower than the majority of the biosensors exposed here, except for those reported in [ 23 , 35 , 41 ] and [ 45 ], which have slightly lower limits of detection in the same order of magnitude (micromolar).…”

Co3O4 nanocubes decorated single-walled carbon nanotubes for efficient electrochemical non-enzymatic glucose sensing

“…It is important to note that nanocubes of cobalt oxide attached with CNTs increased surface area and helped in the measurement of electrons by changing the oxidation of Co +3 to Co +4 which eventually oxidized the glucose into gluconoactone. The electrochemical surface area of Co 3 O 4 /SWCNT/GCE was calculated from peak current obtained by the cyclic voltammograms in ferro/ferricyanide [Fe(CN) 6 ] 3−/4− using the following Randels-SevicK equation [2].…”

“…[1]. In recent years, numerous efforts have been made to formulate glucose-sensing techniques including electrochemical [2], chemiluminescence, surface-enhanced Raman scattering and many other [3]. Among these, the electrochemical strategies have proved to be the most realistic and effective protocol for the detection of blood glucose levels.…”