scholarly journals In vivo molecular sensing in diabetes mellitus: an implantable glucose sensor with direct electron transfer

Diabetologia ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 213-217 ◽  
Author(s):  
J. C. Pickup ◽  
G. W. Shaw ◽  
D. J. Claremont
Keyword(s):  
Diabetes Mellitus ◽  
Electron Transfer ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Molecular Sensing

In Vitro Evaluation of Miniaturized Amperometric Enzyme Sensor Based on the Direct Electron Transfer Principle for Continuous Glucose Monitoring

2022 ◽  
pp. 193229682110706
Author(s):  
Yutaro Inoue ◽  
Yasuhide Kusaka ◽  
Kotaro Shinozaki ◽  
Inyoung Lee ◽  
Koji Sode
Keyword(s):  
Electron Transfer ◽  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Glucose Dehydrogenase ◽  
Glucose Monitoring ◽  
Reference Electrode ◽  
Enzyme Sensor

Background: The bacterial derived flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase (FADGDH) is the most promising enzyme for the third-generation principle-based enzyme sensor for continuous glucose monitoring (CGM). Due to the ability of the enzyme to transfer electrons directly to the electrode, recognized as direct electron transfer (DET)-type FADGDH, although no investigation has been reported about DET-type FADGDH employed on a miniaturized integrated electrode. Methods: The miniaturized integrated electrode was formed by sputtering gold (Au) onto a flexible film with 0.1 mm in thickness and divided into 3 parts. After an insulation layer was laminated, 3 openings for a working electrode, a counter electrode and a reference electrode were formed by dry etching. A reagent mix containing 1.2 × 10−4 Unit of DET-type FADGDH and carbon particles was deposited. The long-term stability of sensor was evaluated by continuous operation, and its performance was also evaluated in the presence of acetaminophen and the change in oxygen partial pressure (pO2) level. Results: The amperometric response of the sensor showed a linear response to glucose concentration up to 500 mg/dL without significant change of the response over an 11-day continuous measurement. Moreover, the effect of acetaminophen and pO2 on the response were negligible. Conclusions: These results indicate the superb potential of the DET-type FADGDH-based sensor with the combination of a miniaturized integrated electrode. Thus, the described miniaturized DET-type glucose sensor for CGM will be a promising tool for effective glycemic control. This will be further investigated using an in vivo study.

Bioconversion of Carbon Monoxide to Formate Using Artificially Designed Carbon Monoxide:Formate Oxidoreductase in Hyperthermophilic Archaea

2021 ◽  
Author(s):  
Jae Kyu Lim ◽  
Ji-In Yang ◽  
Yun Jae Kim ◽  
Yeong-Jun Park ◽  
Yong Hwan Kim
Keyword(s):  
Carbon Monoxide ◽  
Electron Transfer ◽  
Fusion Protein ◽  
Direct Electron Transfer ◽  
Co2 Reduction ◽  
Hyperthermophilic Archaea ◽  
Production Activity ◽  
Formate Production

Abstract Ferredoxin-dependent metabolic engineering of electron transfer circuits has been developed to enhance redox efficiency in the field of synthetic biology, e.g., for hydrogen production and for reduction of flavoproteins or NAD(P)+. Here, we present the bioconversion of carbon monoxide (CO) gas to formate via a synthetic CO:formate oxidoreductase (CFOR), designed as an enzyme complex for direct electron transfer between noninteracting CO dehydrogenase and formate dehydrogenase using an electron-transferring Fe-S fusion protein. The CFOR-introduced Thermococcus onnurineus mutant strains showed CO-dependent formate production in vivo and in vitro. The formate production rate from purified CFOR complex and specific formate productivity from the bioreactor were 348 ± 34 μmol/mg/min and 90.2 ± 20.4 mmol/g-cells/h, respectively. The CO-dependent CO2 reduction/formate production activity of synthetic CFOR was confirmed, indicating that direct electron transfer between two unrelated dehydrogenases was feasible via mediation of the FeS-FeS fusion protein.

scholarly journals Engineered Glucose Oxidase Capable of Quasi-Direct Electron Transfer after a Quick-and-Easy Modification with a Mediator

2020 ◽  
Vol 21 (3) ◽  
pp. 1137 ◽  
Author(s):  
Nanami Suzuki ◽  
Jinhee Lee ◽  
Noya Loew ◽  
Yuka Takahashi-Inose ◽  
Junko Okuda-Shimazaki ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Glucose Oxidase ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Glucose Monitoring ◽  
Single Step ◽  
Redox Mediator ◽  
Electrochemically Active ◽  
Phenazine Ethosulfate ◽  
The Impact

Glucose oxidase (GOx) has been widely utilized for monitoring glycemic levels due to its availability, high activity, and specificity toward glucose. Among the three generations of electrochemical glucose sensor principles, direct electron transfer (DET)-based third-generation sensors are considered the ideal principle since the measurements can be carried out in the absence of a free redox mediator in the solution without the impact of oxygen and at a low enough potential for amperometric measurement to avoid the effect of electrochemically active interferences. However, natural GOx is not capable of DET. Therefore, a simple and rapid strategy to create DET-capable GOx is desired. In this study, we designed engineered GOx, which was made readily available for single-step modification with a redox mediator (phenazine ethosulfate, PES) on its surface via a lysine residue rationally introduced into the enzyme. Thus, PES-modified engineered GOx showed a quasi-DET response upon the addition of glucose. This strategy and the obtained results will contribute to the further development of quasi-DET GOx-based glucose monitoring dedicated to precise and accurate glycemic control for diabetic patient care.

Graphene Quantum Dots Electrochemistry and Development of Ultrasensitive Enzymatic Glucose Sensor

MRS Advances ◽  
2018 ◽  
Vol 3 (15-16) ◽  
pp. 831-847 ◽  
Author(s):  
Sanju Gupta ◽  
Tyler Smith ◽  
Alexander Banaszak ◽  
John Boeckl
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Cyclic Voltammetry ◽  
Glucose Sensor ◽  
Limit Of Detection ◽  
Direct Electron Transfer ◽  
Graphene Quantum Dots ◽  
Optimal Size ◽  
Sensing Applications ◽  
Edge Site

AbstractGraphene quantum dots (GQDs) - zero-dimensional materials - are sheets of a few nanometers in lateral dimension and exhibit quantum confinement and edge site effects where sp2-bonded carbon nanocore surrounded with edged plane functional moieties is promising as advanced electroactive sensing platforms. In this work, GQDs are synthesized by solvothermal and hydrothermal techniques, with optimal size of 5 nm. Their potential in fundamental (direct electron transfer) and applied (enzymatic glucose biosensor) electrochemistry are demonstrated. Glucose oxidase (GOx) immobilized on glassy carbon (GC) electrodes modified with GQDs are investigated by means of cyclic voltammetry, differential pulse voltammetry, and amperometry. Well-defined quasi-reversible redox peaks observed under various electrochemical parameters helped to determine diffusion coefficient (D) and first-order electron transfer rate (kET). The cyclic voltammetry curves showed homogeneous ion transport for GQD with D ranging between 8.45 × 10−9 m2 s−1 and 3 × 10−8 m2 s−1 following GO < rGO < GQD < GQD (with FcMeOH as redox probe) < GOx/rGO < GOx/GO < HRP/GQDs < GOx/GQDs. The developed GOx-GQDs biosensor responds efficiently and linearly to the presence of glucose over concentrations ranging 10 μM and 3 mM with limit of detection 1.35 μM and sensitivity 0.00769 μA μM−1·cm−2 as compared with rGO (0.025 μA μM−1 cm−2, 4.16 μM) and GO (0.064 μA μM−1 cm−2, 4.82 μM) nanosheets. The high performance and stability of GQDs is attributed to sufficiently large surface-to-volume ratio, excellent biocompatibility, abundant hydrophilic edge site density, and partially hydrophobic planar sites that favors GOx adsorption on the electrode surface and versatile architectures to ensure rapid charge transfer and electron/ion conduction (<10 ms). We also carried out similar studies with other enzymatic protein biomolecules on electrode surfaces prepared from GQD precursors for electrochemical comparison, thus opening up potential sensing applications in medicine as well as bio-nanotechnology.

The Continuous 3 Month Operation of Open Circuit Potential Based Glucose Sensor Employing Direct Electron Transfer Type Fad Dependent Glucose Dehydrogenase

2020 ◽  
Vol MA2020-02 (44) ◽  
pp. 2779-2779
Author(s):  
Inyoung Lee ◽  
Junko Shimazaki ◽  
Wakako Tsugawa ◽  
Kazunori Ikebukuro ◽  
Jeffrey E Dick ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Open Circuit Potential ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Glucose Dehydrogenase ◽  
Open Circuit
Sign in / Sign up

Export Citation Format

Share Document