scholarly journals Carbon nanofiber modified with osmium based redox polymer for glucose sensing

2017 ◽  
Vol 7 (4) ◽  
pp. 181-191 ◽  
Author(s):  
Amos Mugweru ◽  
Reaz Mahmud ◽  
Kartik Ghosh ◽  
Adam Wanekaya
Keyword(s):  
Glucose Oxidase ◽  
Carbon Nanofibers ◽  
Carbon Nanofiber ◽  
Energy Dispersive Spectrometer ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Redox Polymer ◽  
Glucose Determination ◽  
Km Value ◽  
Oxidase Enzyme

Electrochemical detection of glucose was performed on carbon nanofibers containing an osmium based redox polymer and using glucose oxidase enzyme. Redox polymer assembled on the nanofibers provided a more stable support that preserved enzyme activity and promoted the electrical communication to the glassy carbon electrode. The morphologies, structures, and electrochemical behavior of the redox polymer modified nanofibers were characterized by scanning electron microscope, energy dispersive spectrometer and voltammetry. The glucose oxidase showed excellent communication with redox polymer as observed with the increased activity toward glucose. Both cyclic voltammetry and amperometry showed a linear response with glucose concentration.  The linear range for glucose determination was from 1 to 12 mM with a relatively high sensitivity of 0.20±0.01 μA mM−1 for glucose oxidase in carbon nanofibers and 0.10±0.01 μA mM−1 without carbon nanofibers. The apparent Michaelis–Menten constant (Km) for glucose oxidase with carbon nanofibers was 0.99 mM. On the other hand, the Km value for the glucose oxidase without the nanofibers was 4.90 mM.

scholarly journals A flexible and highly sensitive pressure sensor based on three-dimensional electrospun carbon nanofibers

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 13898-13905
Author(s):  
Chuan Cai ◽  
He Gong ◽  
Weiping Li ◽  
Feng Gao ◽  
Qiushi Jiang ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Pressure Sensor ◽  
Carbon Nanofiber ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Highly Sensitive ◽  
Sensitive Pressure

A three-dimensional electrospun carbon nanofiber network was used to measure press strains with high sensitivity.

Electrospun carbon nanofiber-supported Pt–Pd alloy composites for oxygen reduction

2010 ◽  
Vol 25 (7) ◽  
pp. 1329-1335 ◽  
Author(s):  
Zhan Lin ◽  
Liwen Ji ◽  
Ozan Toprakci ◽  
Wendy Krause ◽  
Xiangwu Zhang
Keyword(s):  
Carbon Nanofibers ◽  
Photoelectron Spectroscopy ◽  
Carbon Nanofiber ◽  
Energy Dispersive Spectrometer ◽  
Cyclic Voltammograms ◽  
Alloy Nanoparticles ◽  
Electrocatalytic Reduction ◽  
Nanofiber Composite ◽  
Time Scanning ◽  
Pd Alloy

Carbon nanofiber-supported Pt–Pd alloy composites were prepared by co-electrodepositing Pt–Pd alloy nanoparticles directly onto electrospun carbon nanofibers. The morphology and size of Pt–Pd alloy nanoparticles were controlled by the surface treatment of carbon nanofibers and the electrodeposition duration time. Scanning electron microscopy/energy dispersive spectrometer (SEM)/(EDS) and x-ray photoelectron spectroscopy (XPS) were used to study the composition of Pt–Pd alloy on the composites, and the co-electrodeposition mechanism of Pt–Pd alloy was investigated. The resultant Pt–Pd/carbon nanofiber composites were characterized by running cyclic voltammograms in oxygen-saturated 0.1 M HClO4 at 25 °C to study their electrocatalytic ability to reduce oxygen. Results show that Pt–Pd/carbon nanofiber composites possess good performance in the electrocatalytic reduction of oxygen. Among all Pt–Pd/carbon nanofibers prepared, the nanofiber composite with a Pt–Pd loading of 0.90 mg/cm2 has the highest electrocatalytic activity by catalyst mass.

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

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2173
Author(s):  
Natalija German ◽  
Almira Ramanaviciene ◽  
Arunas Ramanavicius
Keyword(s):  
Glucose Oxidase ◽  
Conducting Polymer ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Serum Samples ◽  
Glucose Determination ◽  
Constant Potential ◽  
Good Repeatability ◽  
Graphite Rod

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%), and appropriate stability (half-life period (τ1/2) was 22 and 17 days, respectively). The excellent anti-interference ability to ascorbic and uric acids and successful practical application for glucose determination in serum samples was presented for GR/PANI-AuNPs(6 nm)-GOx/GOx electrode.

scholarly journals Development of an Effective and Economic Biosensor for Diabetic Blood Monitoring Based on MWCNTs, Artificial Redox Mediator Ferrocene, Nafion Polymer and a Local Extracted and Purified Glucose Oxidase Enzyme from Penicillium Notatum F-158 Fungus

2021 ◽  
Author(s):  
Hanaa El-Desoky ◽  
Ashraf Koleeb ◽  
Roqaya Bassuiny ◽  
Tarek Mohamed
Keyword(s):  
Glucose Oxidase ◽  
Redox Mediator ◽  
Enzymatic Oxidation ◽  
Layer By Layer ◽  
Plasma Samples ◽  
Penicillium Notatum ◽  
Glucose Determination ◽  
Fruit Samples ◽  
Oxidase Enzyme ◽  
Orange Fruit

Abstract Enhancement of the properties of glucose oxidase (GOx) enzyme is still receiving attention due to its extensive applications. Eight different fungal strains were isolated from soil and orange fruit samples for inexpensive GOx production. Penicillium notatum F-158 (P. notatum) strain produced a remarkable amount of GOx. Its culture condition was optimized for optimum GOx production. GOx was purified and its activity, stability and kinetic parameters were studied. An effective biosensor {GCE/[MWCNTs–Fc–GOx(FAD)–NF]} based on layer by layer immbolization of MWCNTs, aritificial ferrocene (Fc) redox mediator, extracted P. notatum GOx enzyme and nafion polymer (NF) on glassy carbon electrode (GCE) surface was developed for glucose determination. Fc acts as an electron relay between enzyme and MWCNTs/GCE. The synergy of MWCNTs and Fc enhances the electrocatalytic action of Fc to the enzymatic oxidation of glucose. Low potential (+0.3V) of Fc applied in amperometric measurements avoids interference of the main electroactive substances present in the real plasma samples. This biosensor showed broad linear ranges {2.80×10-4 to 14.99×10-3 M} and low detection limit (8.68×10-6 M) for glucose determination. The achieved glucose concentrations in six plasma samples are consistent with normal values in human blood indicating that such biosensor could be used clinically.

Carbon Nanofiber-Network Sensor Films for Strain Measurement in Composites

2008 ◽  
Vol 1129 ◽  
Author(s):  
Nguyen Q Nguyen ◽  
Sangyoon Lee ◽  
Nikhil Gupta
Keyword(s):  
Carbon Nanofibers ◽  
Strain Measurement ◽  
Carbon Nanofiber ◽  
Force Measurement ◽  
Low Cost ◽  
High Sensitivity ◽  
Adhesively Bonded ◽  
Sensor Film ◽  
Experimental Scheme ◽  
Efficient Alternative

AbstractA carbon nanofiber-based sensor film is designed and calibrated for force measurement. The sensor is designed for use in structural health monitoring of composite materials. The sensing scheme is based on creating a network of carbon nanofibers on the surface of the composite material. In the experimental scheme a patch of nanofiber reinforced epoxy resin film is developed and adhesively bonded to the laminate. The extension of the sensor film due to the applied force leads to a change in the connectivity of carbon nanofibers in the film, resulting in the change in the resistance of the network. Results show that such sensing schemes have high sensitivity and repeatability. Use of nanofibers can provide a low cost and more efficient alternative to other sensor films that rely on carbon nanotubes.

Cytocompatibility of Carbon Nanofiber Materials for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Carbon Fiber ◽  
Surface Energy ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Carbon Nanofiber ◽  
Fiber Composite ◽  
Scar Tissue ◽  
Pc 12 Cells ◽  
Low Surface Energy ◽  
Poly Carbonate

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.

Cytocompatibility and Material Properties of Poly-carbonate Urethane/Carbon Nanofiber Composites for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Material Properties ◽  
Carbon Nanofiber ◽  
Scar Tissue ◽  
Tissue Response ◽  
Positive Interactions ◽  
Weight Percentage ◽  
Poly Carbonate

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.

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