On‐line amperometric assay of glucose, <scp>L</scp>‐glutamate, and acetylcholine using microdialysis probes and immobilized enzyme reactors

Yao, Takeshi; Suzuki, Seita; Nishino, Hirohito; Nakahara, Tsutomu

doi:10.1002/elan.1140071203

Cited by 34 publications

(33 citation statements)

References 11 publications

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“…14 A number of sensor types have been developed for the measurement of Glu based on a variety of metabolic enzymes. [15][16][17][18][19][20] Attention has focused mainly on the use of l-glutamate oxidase (GluOx) that has FAD as the redox centre and molecular oxygen as a co-substrate, 21 producing hydrogen peroxide that can be detected amperometrically 19,20,[22][23][24][25][26][27][28][29][30] or spectroscopically. 31,32 The oxidative deamination catalysed by GluOx 21 can be represented by the following steps: l-Glutamate + H 2 O + GluOx/FAD ?…”

mentioning

confidence: 99%

Biosensor for Neurotransmitter L-Glutamic Acid Designed for Efficient Use of L-Glutamate Oxidase and Effective Rejection of Interference

Ryan

Lowry²,

O’Neill³

1997

Analyst

124

179

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An amperometric biosensor for l-glutamic acid (Glu) was constructed by the adsorption and dip coating of l-glutamate oxidase (GluOx, 200 U ml 21 phosphate buffer, pH 7.4) onto 60-mm radius Teflon-coated Pt wire (1 mm exposed length). The enzyme was then trapped on the surface by electropolymerisation of o-phenylenediamine that also served to block electroactive interference. This procedure afforded electrodes with similar substrate sensitivity compared with the classical approach of immobilising enzyme from a solution of monomer, and represents an approximately 10 000-fold increase in the yield of biosensors from a batch of enzyme. A number of strategies were examined to enhance the sensitivity and selectivity of the Pt/PPD/GluOx sensors operating at 0.7 V versus SCE. Pre-coating the Pt with lipid and incorporation of the protein bovine serum albumin into the polymer matrix were found to improve the performance of the electrode. The sensors had a fast response time, high sensitivity to Glu, with an LOD of about 0.3 mmol l 21 , and possessed selectivity characteristics suggesting that monitoring Glu in biological tissues in vivo may be feasible.

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mentioning

confidence: 99%

Biosensor for Neurotransmitter L-Glutamic Acid Designed for Efficient Use of L-Glutamate Oxidase and Effective Rejection of Interference

Ryan

Lowry²,

O’Neill³

1997

Analyst

124

179

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“…We reported before on a continuous-flow system 8 which makes possible the on-line monitoring of glucose, L-glutamate, and acetylcholine. This method is based on the use of a microdialysis probe in combination with an immobilized enzyme reactor.…”

Section: 2mentioning

confidence: 99%

“…furnished with a small nylon net (350 mesh) at each end, and activated by a glutaraldehyde treatment, as previously described. 8 Two mixed solutions of GlOD and GlDH from different sources were circulated through two separately activated CPG reactors, respectively. By this immobilization procedure, two enzyme reactors (GlOD/GlDH (1.4.1.3) and GlOD/GlDH (1.4.1.4) coimmobilized reactors) were prepared.…”

Section: Preparation Of Immobilized Reactorsmentioning

confidence: 99%

“…The design was almost identical to that described before. 8 The saline-phosphate buffer was pumped at a constant flow (2 µl min -1 ) into the dialysis probe with a microsyringe pump (Eicom EP-60). Ammonium phosphate buffer (0.1 mol dm -3 , pH 7.5) containing 0.3 mmol dm -3 NADPH was also pumped at 8 µl min -1 with a doubleplunger µl pump.…”

Section: Apparatus and Proceduresmentioning

confidence: 99%

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Micro-flow in vivo Analysis of l-Glutamate with an On-line Enzyme Amplifier Based on Substrate Recycling

Yao

Nanjyo

Nishino³

2001

ANAL. SCI.

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“…Similar sensors were applied to the real-time monitoring of lactate in the subcutaneous tissue of rabbits and humans through the use of microdialysis sampling and a lactate amperometric sensor; 42 glucose was monitored continuously with a glucose-oxidase-immobilized enzyme reactor. 43 However, biosensors are not always used for continuous monitoring. Using injection valves, discrete microdialysis samples were injected into flow injection systems and analyzed with amperometric-based biosensors for L-lactate 44 and glucose.…”

Section: Non-separation-based Sampling Approachesmentioning

confidence: 99%

Pharmacokinetic and Metabolism Studies Using Microdialysis Sampling

Hansen

Davies

Lunte

et al. 1999

Journal of Pharmaceutical Sciences

106

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Introduction ADME (adsorption, distribution, metabolism, elimination) studies on new drug entities, toxicological studies on environmental contaminants, and evaluation of chemicals in the workplace all involve gathering similar types of information. Such studies rely on a combination of in vitro, ex vivo, and in vivo techniques. Among the in vitro and ex vivo systems are isolated enzymes, microsomes, cell cultures, tissue homogenates, tissue slices, and isolated organs. Information about the role of specific enzymes and tissues, types of intermediates formed, and pathways for xenobiotic biotransformation are gained through these types of studies. However, because they represent parts rather than the whole physiological system, the types of information gained do not reflect the entire scheme of biotransformation within the intact organism.Traditional in vivo techniques include sampling blood and other biological fluids, analysis of elimination products to determine final disposition of the parent compound and metabolites, and tissue sampling requiring one or more animals per time point. These studies provide general information about the metabolism and final disposition of a compound, but do not offer details about specific enzymes, intermediates, or in vivo metabolic pathways. An overall limitation to traditional approaches is that results obtained in vitro sometimes do not correlate with those found in vivo.Microdialysis sampling has several characteristics that complement traditional in vitro and in vivo pharmacokinetic and metabolism techniques. This approach is accomplished by implanting a probe consisting of a hollow fiber dialysis membrane into the organ or biological matrix of interest. The short length of hollow fiber is affixed to pieces of narrow bore tubing that serve as inlet and oulet conduits for the probe. A solution, termed the perfusate, is pumped slowly through the probe. The perfusate is an aqueous solution that closely matches the ionic composition of the extracellular fluid (ECF). When the perfusate is correctly matched to the ECF, there should be no net exchange of water or ions across the membrane. Low molecular weight compounds can diffuse into or out of the probe lumen in response to concentration gradients and are pumped to the analysis system. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptA diagram of the process is shown in Figure 1. For clarity, the diagram shows only one analyte (A), although several compounds are typically sampled at the same time in a microdialysis experiment. Large molecules such as proteins (P) and small molecules bound to proteins (P-A) are excluded by the membrane. Those molecules entering the lumen of the membrane are swept along by the perfusate and exit the probe. The solution leaving the probe, termed the dialysate, is collected for analysis. The probe can be thought of as an artificial blood vessel in that it can both deliver and remove compounds from the local area. Delivery of the parent compound via the probe permits study o...

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On‐line amperometric assay of glucose, L‐glutamate, and acetylcholine using microdialysis probes and immobilized enzyme reactors

Cited by 34 publications

References 11 publications

Biosensor for Neurotransmitter L-Glutamic Acid Designed for Efficient Use of L-Glutamate Oxidase and Effective Rejection of Interference

Biosensor for Neurotransmitter L-Glutamic Acid Designed for Efficient Use of L-Glutamate Oxidase and Effective Rejection of Interference

Micro-flow in vivo Analysis of l-Glutamate with an On-line Enzyme Amplifier Based on Substrate Recycling

Pharmacokinetic and Metabolism Studies Using Microdialysis Sampling

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