Ferrocene-Modified Polyelectrolyte Film-Coated Electrode and Its Application in Glucose Detection

A polyelectrolyte film-coated electrode for the quantitative detection of glucose was reported. Carbon nanotubes, graphene oxide and polyelectrolyte with a ferrocenyl group were used to modify an enzyme electrode to facilitate the electron transfer between glucose oxidase and the electrode. Cyclic voltammetry and amperometric methods were adopted to investigate the effects of different polyelectrolytes and carbon nanomaterials on the electrochemical properties of enzyme electrodes. The results indicate that the ferrocenyl groups on a polyelectrolyte skeleton act as a mediator between the redox center of glucose oxidase and the electrode, which efficiently enhances the electron transfer between a glassy carbon electrode and glucose oxidase. The calibration curve of the sensor shows a linear range from 0.2 to 5 mM for glucose response. The sensor can achieve 95% of the steady-state current within 10 s. The electrodes also present high operational stability and long-term storage stability.

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Immobilized glucose oxidase used in the continuous-flow determination of serum glucose.

Clinical Chemistry ◽

10.1093/clinchem/22.7.1017 ◽

1976 ◽

Vol 22 (7) ◽

pp. 1017-1023 ◽

Cited By ~ 23

Author(s):

L P León ◽

S Narayanan ◽

R Dellenbach ◽

C Horvath

Keyword(s):

Glucose Oxidase ◽

Continuous Flow ◽

Serum Glucose ◽

Long Term Storage ◽

Free Glucose ◽

Immobilized Glucose Oxidase ◽

Analytical System ◽

Single Enzyme

Abstract We used a tubular glucose-oxidase wall reactor in the "AutoAnalyzer II" continuous-flow analytical system to determine glucose in blood serum. Sensitivity was high and wash characteristics were satisfactory with use of a 30-cm tube containing immobilized glucose oxidase. Results compared favorably with those of the conventional free-enzyme method. More than 25000 such assays can be performed with a single enzyme tube, which also shows long-term storage stability. Because of the steady-state chemistry 60 samples can be analyzed per hour. The linearity of the method is excellent and sample interaction from 5.0 to 1.0 g/liter is less than 5%. Results correlate well (greater than 0.993) with those obtained with both the neocuproine method used in the "SMA 12/60" multichannel analytical system and the free glucose oxidase method used in the AutoAnalyzer.

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Electrochemical Study of Enzymatic Glucose Sensors Biocatalyst: Thermal Degradation after Long-Term Storage

Chemosensors ◽

10.3390/chemosensors6040053 ◽

2018 ◽

Vol 6 (4) ◽

pp. 53 ◽

Cited By ~ 5

Author(s):

Marcelinus Christwardana ◽

Domenico Frattini

Keyword(s):

Thermal Degradation ◽

Storage Temperature ◽

Protein Denaturation ◽

Transfer Constant ◽

Glucose Response ◽

C Storage ◽

Long Term Storage ◽

Glucose Oxidation Reaction ◽

Term Storage

The thermal degradation related to stability in long-term storage of a carbon nanotube-based biosensor has been investigated. The effect of storage temperature on detachment and denaturation of glucose oxidase (GOx) biocatalyst has been proved. The carbon nanotubes (CNTs) coated with polyethyleneimine (PEI) as entrapping polymer to attract more GOx to form a durable and layered CNT/PEI/GOx structure is used for long-term storage to minimize GOx detachment from the structure and minimize the possibility of enzyme and protein denaturation. After 120 days, the glucose response of the CNT/PEI/GOx biosensor stored under 4°C is preserved up to 66.7% of its initial value, while under a 25 °C storage the response is maintained up to 41.7%. The enzyme coverage activity of CNT/PEI/GOx stored at 4 °C and 25 °C has decreased by 31.1% and 51.4%, respectively. Denaturation and detachment of GOx are the common causes of thermal degradation in biosensors under improper storage temperatures, but the presence of PEI in the structure can slow-down these phenomena. Moreover, the electrons transfer constant of CNT/PEI/GOx biocatalyst stored at 4 °C and 25 °C were 7.5 ± 0.5 s−1 and 6.6 ± 0.3 s−1, respectively, indicating that also electrons mobility is damaged by detachment and denaturation of enzyme protein and the detection of glucose from the glucose oxidation reaction (GOR) is compromised.

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Intramolecular Electron Transfer through Poly-Ferrocenyl Glucose Oxidase Conjugates to Carbon Electrodes: 2. Mechanistic Understanding of Long-Term Stability

Electrochimica Acta ◽

10.1016/j.electacta.2017.06.066 ◽

2017 ◽

Vol 246 ◽

pp. 294-302 ◽

Cited By ~ 1

Author(s):

Alan S. Campbell ◽

Mohammad F. Islam ◽

Alan J. Russell

Keyword(s):

Electron Transfer ◽

Glucose Oxidase ◽

Carbon Electrodes ◽

Intramolecular Electron Transfer ◽

Term Stability ◽

Long Term Stability ◽

Mechanistic Understanding

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Glucose oxidase and Au nanocluster co-encapsulated metal–organic frameworks as a sensitive colorimetric sensor for glucose based on a cascade reaction

New Journal of Chemistry ◽

10.1039/c9nj06339k ◽

2020 ◽

Vol 44 (31) ◽

pp. 13344-13349

Author(s):

Jingtian Chi ◽

Manli Guo ◽

Chi Zhang ◽

Yuanhong Zhang ◽

Shiyun Ai ◽

...

Keyword(s):

Glucose Oxidase ◽

Glucose Sensor ◽

Storage Stability ◽

Metal Organic Frameworks ◽

High Sensitivity ◽

Long Term Storage ◽

Sensitivity And Selectivity ◽

Metal Organic ◽

Term Storage

The GOx & AuNCs@ZIF-8 composite was simply obtained as a colorimetric glucose sensor with high sensitivity and selectivity and long-term storage stability.

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Preparation And elemental analysis of ancient fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126846 ◽

1987 ◽

Vol 45 ◽

pp. 410-411

Author(s):

Allen Angel ◽

Kathryn A. Jakes

Keyword(s):

Cross Sections ◽

Physical Structure ◽

Energy Dispersive ◽

Archaeological Sites ◽

X Ray ◽

Long Term Storage ◽

Backscattered Electron ◽

Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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Modelling of Moisture Movement in Wood during Outdoor Storage

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2001.6.1.15210 ◽

2001 ◽

Vol 6 (2) ◽

pp. 3-14 ◽

Cited By ~ 23

Author(s):

R. Baronas ◽

F. Ivanauskas ◽

I. Juodeikienė ◽

A. Kajalavičius

Keyword(s):

Experimental Data ◽

Finite Difference ◽

Climatic Conditions ◽

Two Dimensional ◽

Moisture Movement ◽

Finite Difference Technique ◽

Long Term Storage ◽

Space Formulation ◽

Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

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