Functionalized single-walled carbon nanotubes/polypyrrole composites for amperometric glucose biosensors

Abstract

This article reports an amperometric glucose biosensor based on a new type of nanocomposite of polypyrrole (PPY) with p-phenyl sulfonate-functionalized single-walled carbon nanotubes (SWCNTs-PhSO3−). An environmentally friendly functionalization procedure of the SWCNTs in the presence of substituted aniline and an oxidative species was adopted. The nanocomposite-modified electrode exhibited excellent electrocatalytic activities towards the reduction or oxidation of H2O2. This feature allowed us to use it as bioplatform on which glucose oxidase (GOx) was immobilized by entrapment in an electropolymerized PPY/SWCNTs-PhSO3− film for the construction of the glucose biosensor. The amperometric detection of glucose was assayed by applying a constant electrode potential value necessary to oxidize or reduce the enzymatically produced H2O2 with minimal interference from the possible coexisting electroactive compounds. With the introduction of a thin film of Prussian blue (PB) at the substrate electrode surface, the PPY/GOx/SWCNTs-PhSO3−/PB system shows synergy between the PB and functionalized SWCNTs which amplifies greatly the electrode sensitivity when operated at low potentials. The biosensor showed good analytical performances in terms of low detection (0.01 mM), high sensitivity (approximately 6 μA mM−1 cm−2), and wide linear range (0.02 to 6 mM). In addition, the effects of applied potential, the electroactive interference, and the stability of the biosensor were discussed. The facile procedure of immobilizing GOx used in the present work can promote the development of other oxidase-based biosensors which could have a practical application in clinical, food, and environmental analysis.

Highly sensitive electrodic materials based on Pt nanoflowers grown on Pt nanospheres for biosensor development

“…Moreover, high working potentials mean high energy consumption. Substrate contamination by adsorbed molecules on the flat surface is another disadvantage usually met [8,9]. To overcome these problems, the development of hybrid nanomaterials have attracted high interest for the combination of the properties of each component that exhibit better catalytic performance than the single component [10].…”

A bimetallic nanocoral Au decorated with Pt nanoflowers (bio)sensor for H2O2 detection at low potential

“…In the last years the use of nanostructured-based modified electrodes able to drastically lower the applied potential gave new interest on the use of these biodevices [1,2]. In fact, although the first generation biosensors are still widely used, the principal drawback is that H 2 O 2 is sensed at a high potential (+0.70 V vs. Ag|AgCl) on most electrode materials and possible interfering components present in biological fluids such as ascorbic acid (AA), uric acid (UA) and acetaminophen (APAP) can be oxidized at this high potential and generate a faradic current that interferes in the measurement of the analyte [3,4]. In order to minimize the oxidation of interfering components, it is preferred to work in a potential range from À0.2 to +0.15 V vs. Ag|AgCl [5,6].…”

“…It is known that many enzymes require neutral or alkaine pH but at this pH value Prussian Blue is unstable and will deteriorate [7]. The main disadvantages of the bienzymatic biosensor are the instability due to the presence of two enzymes and the difficulty in the binding of peroxidases onto solid surfaces [3]. With the advent of nanotechnology, an interest was focused on developing new nanomaterials and to employ them for an improved sensor sensitivity and for a preservation of the native structure of the enzyme when immobilized onto the electrode surface [18][19][20][21][22][23][24][25].…”

Poly(N-Methylpyrrole)-Chitosan layers for Glucose Oxidase Immobilization for Amperometric Glucose Biosensor Design

“…Therefore, chitosan can be used as a gel matrix for enzyme immobilization through GAL or another reagent . Several electropolymers were used to fabricate the glucose biosensor such as polypyrrole (PPy) (Ozyilmaz et al 2011, Raicopol et al 2013, Olea et al 2008, polyaniline (PANI) (Ozdemir et al 2010, Yao et al 2015, Tang et al 2015, poly(o-anisidine) (POA) (Savale & Shirsat 2009, Borole et al 2007), poly(o-phenylenediamine) (Rothwell et al 2010), polythophen derivative (Abasiyanik et al 2010). …”