Glucose, biosensors

First amperometric biosensor glucose oxidase-based enzyme electrode for glucose [6]... 

BOD biosensor, glucose analyzer ESAT 6660-2 Q-Sense E4, Q-Sense Modules, etc. 

In another attempt for fabrication of an enz5mie-based biosensor, glucose oxidase (GOD) was immobilized in PEDOT-PSS pol5mier deposited on carbon cloth (CCl) substrate modified with... 

Keywords-. Conducting polymers, nanocomposites, biosensors, immunosen-sors, bioaffinity sensors, DNA biosensors, cholesterol biosensors, glucose biosensors, electrochemical biosensor, sensitivity, response time, recovery time selectivity, reversibility, polyanihne, polypyrrole, graphene, carbon nanotubes, nanoparticles... 

Enzyme sensors for carbohydrates. An enzyme electrode for glucose was the first electrochemical biosensor studied [1] and since then intensive research has taken place, providing new ideas and experiences for the development of other biosensors. Glucose biosensors usually use as a biological component the relatively stable enzyme glucose oxidase, preferably from Aspergillus niger (Fig. 14). This enzyme may serve as a model for all flavin oxidoreductases which can be applied not only for... 

Schematic showing the reactions by which an amperometric biosensor responds to glucose.

This experiment describes the use of a commercially available amperometric biosensor for glucose that utilizes the enzyme glucose oxidase. The concentration of glucose in artificial... 

Wang, J. Macca, C. Use of Blood-Glucose Test Strips for Introducing Enzyme Electrodes and Modern Biosensors, ... 

Commercially available kits for monitoring blood-glucose use an amperometric biosensor incorporating the enzyme glucose oxidase. This experiment describes how such monitors can be adapted to the quantitative analysis of glucose in beverages. 

Biosensors (qv) and DNA probes ate relatively new to the field of diagnostic reagents. Additionally, a neat-infrared (nit) monitoring method (see Infrared TECHNOLOGY AND RAMAN SPECTROSCOPY), a teagenfless, noninvasive system, is under investigation. However, prospects for a nit detection method for glucose and other analytes ate uncertain. 

A compound which is a good choice for an artificial electron relay is one which can reach the reduced FADH2 active site, undergo fast electron transfer, and then transport the electrons to the electrodes as rapidly as possible. Electron-transport rate studies have been done for an enzyme electrode for glucose (G) using interdigitated array electrodes (41). The following mechanism for redox reactions in osmium polymer—GOD biosensor films has... 

The simple cases where one enzyme is employed afford a limited scope of potential targets. Usually two or more enzyme reactions are coupled, as exemplified by the development of a piezoelectricaHy-transduced biocatalytic biosensor that couples two enzyme reactions to detect glucose [492-62-6] ... 

In this biosensor a quartz radio crystal is functionalized with the enzyme glucose-6-phosphate dehydrogenase. As shown in Figure 3, a thin film of Pmssian blue [14038-43-8] C gN gFe, is then coated onto the crystal. 

Fig. 4. Schematic of a multisequence biosensor in which the target glucose is first converted to glucose-6-phosphate, G6P, in the test solution by hexokinase. G6P then reacts selectively with glucose-6-phosphate dehydrogenase immobilized on the quartz crystal surface. Electrons released in the reaction then chemically reduce the Pmssian blue film (see Fig. 3), forcing an uptake of potassium ions. The resulting mass increase is manifested as a...

The dye is excited by light suppHed through the optical fiber (see Fiber optics), and its fluorescence monitored, also via the optical fiber. Because molecular oxygen, O2, quenches the fluorescence of the dyes employed, the iatensity of the fluorescence is related to the concentration of O2 at the surface of the optical fiber. Any glucose present ia the test solution reduces the local O2 concentration because of the immobilized enzyme resulting ia an iacrease ia fluorescence iatensity. This biosensor has a detection limit for glucose of approximately 100 ]lM , response times are on the order of a miaute. 

Entrapment of biochemically reactive molecules into conductive polymer substrates is being used to develop electrochemical biosensors (212). This has proven especially useful for the incorporation of enzymes that retain their specific chemical reactivity. Electropolymerization of pyrrole in an aqueous solution containing glucose oxidase (GO) leads to a polypyrrole in which the GO enzyme is co-deposited with the polymer. These polymer-entrapped GO electrodes have been used as glucose sensors. A direct relationship is seen between the electrode response and the glucose concentration in the solution which was analyzed with a typical measurement taking between 20 to 40 s. 

Electrodes may also be rendered selective to more complex analytes using enzyme or other overcoats (see Biopolymers, analytical techniques Biosensors). The enzyme converts the analyte into a detectable ion or gas. Glucose and blood urea nitrogen sensors can be made in this way. 

Several biosensors are commercially available. One of the most useful is the glucose sensor. The standard sensor determines glucose concentration based on the glucose oxidase enzyme. The chemical reaction for oxidation of glucose is ... 

FIGURE 6-4 Schematic of a first-generation glucose biosensor (based on a probe manufactured by YSI Inc.). 

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