Effective and Functional Surface Design for Biosensing Applications Based on a Novel Conducting Polymer and PMMA/Clay Nanocomposite (original) (raw)

A benzimidazole-based conducting polymer and a PMMA–clay nanocomposite containing biosensor platform for glucose sensing

Synthetic Metals, 2015

ABSTRACT Development of materials composed of polymer–clay nanocomposites (PCN) and conducting polymers attracts great interest and preferred in various applications. Hereby, polymethylmethacrylate (PMMA) layered silicate nanocomposites were prepared by in-situ suspension polymerization by grafting PMMA with laponite using a suitable grafting agent. The properties of the as-synthesized PCN materials are characterized by differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA) and gel permeation chromatography (GPC). A conducting polymer; poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-7-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)-2-benzyl-1H-benzo[d]imidazole) (poly(BIPE)) and a PMMA–clay nanocomposite with 2-(methacryloyloxy) ethyltrimethylammonium chloride (MTMA) modifier were examined as a platform for biomolecule deposition. Glucose oxidase (GOx, β-d-glucose: oxygen-1-oxidoreductase, EC 1.1.3.4) was chosen as the model enzyme to prepare a scaffold for glucose sensing. Three different sensing strategies; PCN/GOx, poly(BIPE)/GOx and PCN/poly(BIPE)/GOx were analyzed and their biosensor performances were discussed. Surface morphology of the modified electrodes was characterized by scanning electron microscopy (SEM) technique. Electrochemical responses of the enzyme electrodes were monitored at −0.7 V vs. Ag reference electrode by monitoring oxygen consumption in the presence of glucose. After optimum conditions were determined, kinetic and analytical parameters; KMapp, Imax, LOD and sensitivity were investigated for each sensing platform.

Codeposited Poly(benzoxazine) and Os-Complex Modified Polymethacrylate Layers as Immobilization Matrix for Glucose Biosensors

Electroanalysis, 2015

B enzoxazine oligomers synthesizedb yaMannich type reactiono fb isphenolA ,t etraethylenepentamine and formaldehydew ere electrochemically crosslinked in presence of both an Os-complex modified poly-(methacrylate) polymer and glucose oxidase. Thec rosslinking led to the formation of ab iocatalytically active layer on an electrode surface exhibiting aswellingp rocess afteri mmersion in an electrolyte solution containing glucose most likely due to the local decreaseo ft he pH value upon glucose oxidation. Optimization of the poly(benzoxazine) to Os-complex modified poly(methacrylate) ratio wasp erformed leading to ar eagentless glucose biosensor with improved stability.

A Composite Clay Glucose Biosensor Based on an Electrically Connected HRP

Electroanalysis, 2000

A novel bienzyme electrode based on a redox clay matrix is described for the cathodic detection of glucose. Peroxidase (HRP) was immobilized in clay matrix containing graphite particles. In order to electrically connect the immobilized HRP, electropolymerized ®lms of 3,4-dihydroxybenzaldehyde were generated within the composite matrix. The resulting biosensors were applied to the amperometric detection of H 2 O 2 via its electroenzymatic reduction at 0V (vs. SCE). The in¯uence of the biosensor composition on the ef®ciency of H 2 O 2 detection was investigated, the highest sensitivity being 130 mAM 71 cm 72 . The additional immobilization of glucose oxidase in an external clay gel led to a bienzyme electrode for the determination of glucose; the highest sensitivity being 14.95 mAM 71 cm 72 .

Biosensors based on oxidases immobilized in various conducting polymers

Sensors and Actuators B: Chemical, 1995

The electrodeposited organic polymers polypyrrole, poly(N-methylpyrrole), poly(u-phenylenediamine) and polyaniline are compared as matrices for the immobilization of glucose oxidase in the preparation of amperometric glucose biosensors. Enzyme entrapment in the polymer layer is obtained by electrodeposition of polymers from solutions of monomers containing dissolved enzyme. For all examined sensors a useful and almost linear range of response to glucose is observed up to at least 20 mM of glucose. The best sensitivity of response is obtained for a glucose sensor made of poly(o-phenylenediamine) and polypyrrole. A linear response up to 20 mM glucose is also obtained in flow-injection measurements for a glucose/polypyrrole sensor. Poly(o-phenylenediamine) is also used for satisfactory immobilization of choline oxidase in the preparation of a choline sensor, whereas a lactate biosensor has been prepared by immobilization of lactate oxidase in polypyrrole.

Development of a novel biosensor based on a conducting polymer

A new type of amperometric cholesterol biosensor was fabricated to improve the biosensor characteristics such as sensitivity and reliability. For this purpose, a novel immobilization matrix 2-(4-fluorophenyl)-4,7di(thiophene-2-yl)-1H-benzo[d]imidazole (BIPF) was electrochemically deposited on a graphite electrode and used as a matrix for the immobilization of cholesterol oxidase (ChOx). Due to strong π-π stacking of aromatic groups in the structures of polymer backbone and enzyme molecule, one can easily achieve a sensitive and reliable biosensor without using any membrane or covalent bond formation between the enzyme molecules and polymer surface. Moreover, through pendant fluorine group of the polymer, H-bond formation between with enzyme molecules and polymer was generated. Cholesterol was used as the substrate and amperometric response was measured in correlation with cholesterol amount, at À 0.7 V vs. Ag/AgCl in phosphate buffer (pH 7.0). Consequently, optimum conditions for this constructed biosensor were determined. K M app, I max , LOD and sensitivity values were investigated and calculated as 4.0 nM, 2.27 mA, 0.404 mM and 1.47 mA/mM cm 2 , respectively. A novel and accurate cholesterol biosensor was developed for the determination of total cholesterol in food samples.

Dispersed Conducting Polymer Nanocomposites with Glucose Oxidase and Gold Nanoparticles for the Design of Enzymatic Glucose Biosensors

Polymers

Biosensors for the determination of glucose concentration have a great significance in clinical diagnosis, and in the food and pharmaceutics industries. In this research, short-chain polyaniline (PANI) and polypyrrole (Ppy)-based nanocomposites with glucose oxidase (GOx) and 6 nm diameter AuNPs (AuNPs(6 nm)) were deposited on the graphite rod (GR) electrode followed by the immobilization of GOx. Optimal conditions for the modification of GR electrodes by conducting polymer-based nanocomposites and GOx were elaborated. The electrodes were investigated by cyclic voltammetry and constant potential amperometry in the presence of the redox mediator phenazine methosulfate (PMS). The improved enzymatic biosensors based on GR/PANI-AuNPs(6 nm)-GOx/GOx and GR/Ppy-AuNPs(6 nm)-GOx/GOx electrodes were characterized by high sensitivity (65.4 and 55.4 μA mM−1 cm−2), low limit of detection (0.070 and 0.071 mmol L−1), wide linear range (up to 16.5 mmol L−1), good repeatability (RSD 4.67 and 5.89%), ...

4-aminothiophenol-intercalated montmorillonite: Organic-inorganic hybrid material as an immobilization support for biosensors

Sensors and Actuators B-chemical, 2020

Hybrid materials containing organic and inorganic structures are very important because they have the advantages of each of their components. Intercalation of the organic molecule to inorganic structures such as clay allows the preparation of multifunctional new immobilization matrices that contain both the strength properties of the clays and the properties of the organic molecule such as its functional groups (amine, carboxyl or hydroxyl etc.). In this study, 4-aminothiophenol intercalated montmorillonite (4ATP-Mt) was prepared and used as an immobilization layer for the pyranose oxidase (PyOx) enzyme on a glassy carbon (GC) electrode. Firstly, 4ATP intercalation of Mt was carried out, and the success of intercalation was proven using Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), and Thermogravimetric Analysis (TGA) techniques. Then PyOx was immobilized using 4ATP-Mt, BSA and glutaraldehyde as a cross-linker on the surface of GC electrodes. To show the coating steps for the preparation of 4ATP-Mt/PyOx biosensors, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were applied, and surface morphology was visualized by scanning electron microscopy (SEM). After optimization of working conditions, analytical performance parameters were determined for glucose detection. The 4ATP-Mt/PyOx biosensor exhibited a wide linear concentration range between 0.01 and 0.5 mM (LOD: 1.0 μM) for glucose. Additionally, the fabricated 4ATP-Mt/PyOx was assayed for the analysis of glucose in artificial body fluids and drinks.

A biocompatible nanocomposite for glucose sensing

2011

A nanocomposite containing amine functionalized multiwalled carbon nanotubes and a room temperature ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) was prepared and applied for glucose oxidase (GOx) immobilization on glassy carbon electrode. The proposed nanocomposite provided a favorable microenvironment to preserve the bioactivity of GOx. It could also effectively facilitate the enzyme direct electron transfer to the electrode.

A novel promising biomolecule immobilization matrix: Synthesis of functional benzimidazole containing conducting polymer and its biosensor applications

Colloids and Surfaces B: Biointerfaces, 2013

In order to construct a robust covalent binding between biomolecule and immobilization platform in biosensor preparation, a novel functional monomer 4-(4,7-di(thiophen-2-yl)-1Hbenzo[d]imidazol-2-yl)benzaldehyde (BIBA) was designed and successfully synthesized. A c c e p t e d M a n u s c r i p t After electropolymerization of this monomer, electrochemical and spectroelectrochemical properties were investigated in detail. To fabricate the desired biosensor, glucose oxidase (GOx) was immobilized as a model enzyme on the polymer coated graphite electrode with the help of glutaraldehyde (GA). During the immobilization step, an imine bond was formed between the free amino groups of enzyme and aldehyde group of polymer. The surface characterization and morphology were investigated to confirm bioconjugation by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) at each step of biosensor fabrication. The optimized biosensor shows good linearity between 0.02 mM and 1.20 mM and a low limit of detection (LOD) of 2.29 M. Kinetic parameters K m app and I max were determined as 0.94 mM and 10.91 respectively. The biosensor was tested for human blood serum samples.

Palygorskite-poly(o-phenylenediamine) nanocomposite: An enhanced electrochemical platform for glucose biosensing

Applied Clay Science, 2013

Palygorskite (Pal) may be a promising material for enzyme immobilization due to its large surface, high biocompatibility and stability. This attractive material combined with a conducting polymer, poly(ophenylenediamine), was exploited as a platform for the immobilization of glucose oxidase (GOD) using glutaraldehyde as crosslinker, and thus a novel glucose biosensor was obtained. The results of electrochemical impedance spectroscopy (EIS) and SEM indicated the successful entrapment of GOD in the clay polymer nanocomposite (CPN) film. Amperometric detection of glucose was performed by holding the potential at the CPN electrode at 0.6 V for the oxidation of H 2 O 2 generated in the enzymatic reaction. The apparent Michaelis-Menten constant (K M app ) was calculated to be 5.25 mM, which is close to that of the free enzyme. The proposed biosensor exhibited a wide linear range, a low detection limit, a good reproducibility and accepted stability in the determination of glucose, providing a biocompatible platform for glucose biosensing.