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Chmayssem A, Nadolska M, Tubbs E, Sadowska K, Vadgma P, Shitanda I, Tsujimura S, Lattach Y, Peacock M, Tingry S, Marinesco S, Mailley P, Lablanche S, Benhamou PY, Zebda A. Insight into continuous glucose monitoring: from medical basics to commercialized devices. Mikrochim Acta 2023; 190:177. [PMID: 37022500 DOI: 10.1007/s00604-023-05743-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/08/2023] [Indexed: 04/07/2023]
Abstract
According to the latest statistics, more than 537 million people around the world struggle with diabetes and its adverse consequences. As well as acute risks of hypo- or hyper- glycemia, long-term vascular complications may occur, including coronary heart disease or stroke, as well as diabetic nephropathy leading to end-stage disease, neuropathy or retinopathy. Therefore, there is an urgent need to improve diabetes management to reduce the risk of complications but also to improve patient's quality life. The impact of continuous glucose monitoring (CGM) is well recognized, in this regard. The current review aims at introducing the basic principles of glucose sensing, including electrochemical and optical detection, summarizing CGM technology, its requirements, advantages, and disadvantages. The role of CGM systems in the clinical diagnostics/personal testing, difficulties in their utilization, and recommendations are also discussed. In the end, challenges and prospects in future CGM systems are discussed and non-invasive, wearable glucose biosensors are introduced. Though the scope of this review is CGMs and provides information about medical issues and analytical principles, consideration of broader use will be critical in future if the right systems are to be selected for effective diabetes management.
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Affiliation(s)
- Ayman Chmayssem
- UMR 5525, Univ. Grenoble Alpes, CNRS, Grenoble INP, INSERM, TIMC, VetAgro Sup, 38000, Grenoble, France
| | - Małgorzata Nadolska
- Institute of Nanotechnology and Materials Engineering, Faculty of Applied Physics and Mathematics, Gdansk University of Technology, 80-233, Gdansk, Poland
| | - Emily Tubbs
- Univ. Grenoble Alpes, CEA, INSERM, IRIG, 38000, Grenoble, Biomics, France
- Univ. Grenoble Alpes, LBFA and BEeSy, INSERM, U1055, F-38000, Grenoble, France
| | - Kamila Sadowska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4, 02-109, Warsaw, Poland
| | - Pankaj Vadgma
- School of Engineering and Materials Science, Queen Mary University of London, Mile End, London, E1 4NS, UK
| | - Isao Shitanda
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
- Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Seiya Tsujimura
- Japanese-French lAaboratory for Semiconductor physics and Technology (J-F AST)-CNRS-Université Grenoble Alpes-Grenoble, INP-University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8573, Japan
- Division of Material Science, Faculty of Pure and Applied Science, University of Tsukuba, 1-1-1, Tennodai, Ibaraki, Tsukuba, 305-5358, Japan
| | | | - Martin Peacock
- Zimmer and Peacock, Nedre Vei 8, Bldg 24, 3187, Horten, Norway
| | - Sophie Tingry
- Institut Européen Des Membranes, UMR 5635, IEM, Université Montpellier, ENSCM, CNRS, Montpellier, France
| | - Stéphane Marinesco
- Plate-Forme Technologique BELIV, Lyon Neuroscience Research Center, UMR5292, Inserm U1028, CNRS, Univ. Claude-Bernard-Lyon I, 69675, Lyon 08, France
| | - Pascal Mailley
- Univ. Grenoble Alpes, CEA, LETI, 38000, Grenoble, DTBS, France
| | - Sandrine Lablanche
- Univ. Grenoble Alpes, LBFA and BEeSy, INSERM, U1055, F-38000, Grenoble, France
- Department of Endocrinology, Grenoble University Hospital, Univ. Grenoble Alpes, Pôle DigiDune, Grenoble, France
| | - Pierre Yves Benhamou
- Department of Endocrinology, Grenoble University Hospital, Univ. Grenoble Alpes, Pôle DigiDune, Grenoble, France
| | - Abdelkader Zebda
- UMR 5525, Univ. Grenoble Alpes, CNRS, Grenoble INP, INSERM, TIMC, VetAgro Sup, 38000, Grenoble, France.
- Japanese-French lAaboratory for Semiconductor physics and Technology (J-F AST)-CNRS-Université Grenoble Alpes-Grenoble, INP-University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8573, Japan.
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Wang S, Zou X, Wang L, Zhou H, Wu L, Zhang Y, Yao TX, Chen L, Li Y, Zeng Y, Zhang L. Potential preventive markers in the intracerebral hemorrhage process are revealed by serum untargeted metabolomics in mice using hypertensive cerebral microbleeds. Front Endocrinol (Lausanne) 2023; 14:1084858. [PMID: 37152968 PMCID: PMC10159181 DOI: 10.3389/fendo.2023.1084858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Hypertensive cerebral microbleeds (HCMB) may be the early stage of hypertensive intracerebral hemorrhage (HICH), which is a serious threat to health due to its high mortality and disability rates. The early clinical symptoms of HCMB may not be significant. Moreover, it is difficult to achieve early diagnosis and intervention for targeted prevention of HICH. Although hypertension (HTN) is a predisposition for HCMB, it remains unclear whether there is any difference between hypertensive patients with or without HCMB. Therefore, we carried out liquid chromatography-mass spectrometry (LC-MS) to analyze early biomarkers for HCMB in mice with hypertension and to lay the foundation for early prevention of HICH in hypertensive patients. In total, 18 C57 male mice were randomly divided into the HCMB (n = 6), HTN (n = 6), and control groups (CON, n = 6). Hematoxylin-eosin and diaminobenzidine staining were used to assess the reliability of the model. The metabolite expression level and sample category stability were tested using the displacement test of orthogonal partial least squares discriminant analysis (OPLS-DA). Significant differences in metabolites were screened out using variable importance in the projection (VIP > 1), which were determined using the OPLS-DA model and the P-value of the t-test (P < 0.05) combined with the nonparametric rank-sum test. With an area under the curve (AUC) > 0.85 and a P-value of 0.05, the receiver operating characteristic curve (ROC) was used to further screen the distinct metabolites of HCMB. Compared with the HTN and CON groups, the HCMB group had significantly higher blood pressure and lower average body weight (P < 0.05). Through untargeted LC-MS analysis, 93 distinct metabolites were identified in the HCMB (P < 0.05, VIP > 1) group. Among these potential biomarkers, six significantly decreased and eight significantly increased differential metabolites were found. Meanwhile, we found that the HCMB group had statistically distinct arginine and purine metabolism pathways (P < 0.05), and citrulline may be the most significant possible biomarker of HCMB (AUC > 0.85, P < 0.05). All of these potential biomarkers may serve as early biomarkers for HICH in hypertension.
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Affiliation(s)
- Sai Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xuelun Zou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Leiyun Wang
- Department of Pharmacy, Wuhan First Hospital, Wuhan, Hubei, China
| | - Huifang Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lianxu Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yupeng Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tian-Xing Yao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lei Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ye Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yi- Zeng
- Department of Geriatrics, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Le Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Multi-Modal Monitoring Technology for Severe Cerebrovascular Disease of Human Engineering Research Center, Xiangya Hospital, Central South University, Changsha, Hunan, China
- *Correspondence: Le Zhang,
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Wong ZW, Engel T. More than a drug target: Purinergic signalling as a source for diagnostic tools in epilepsy. Neuropharmacology 2023; 222:109303. [PMID: 36309046 DOI: 10.1016/j.neuropharm.2022.109303] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/15/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Epilepsy is one of the most common and disabling chronic neurological diseases affecting people of all ages. Major challenges of epilepsy management include the persistently high percentage of drug-refractoriness among patients, the absence of disease-modifying treatments, and its diagnosis and prognosis. To date, long-term video-electroencephalogram (EEG) recordings remain the gold standard for an epilepsy diagnosis. However, this is very costly, has low throughput, and in some instances has very limited availability. Therefore, much effort is put into the search for non-invasive diagnostic tests. Purinergic signalling, via extracellularly released adenosine triphosphate (ATP), is gaining increasing traction as a therapeutic strategy for epilepsy treatment which is supported by evidence from both experimental models and patients. This includes in particular the ionotropic P2X7 receptor. Besides that, other components from the ATPergic signalling cascade such as the metabotropic P2Y receptors (e.g., P2Y1 receptor) and ATP-release channels (e.g., pannexin-1), have also been shown to contribute to seizures and epilepsy. In addition to the therapeutic potential of purinergic signalling, emerging evidence has also shown its potential as a diagnostic tool. Following seizures and epilepsy, the concentration of purines in the blood and the expression of different compounds of the purinergic signalling cascade are significantly altered. Herein, this review will provide a detailed discussion of recent findings on the diagnostic potential of purinergic signalling for epilepsy management and the prospect of translating it for clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.
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Affiliation(s)
- Zheng Wei Wong
- School of Pharmacy, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland.
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Hassan Oghli A, Soleymanpour A. One-step electrochemical modification of pencil graphite electrode with reduced graphene oxide/phosphotungstic acid/sol–gel, and its application to the trace analysis of lead(II). Microchem J 2022. [DOI: 10.1016/j.microc.2021.107034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Beamer E, Lacey A, Alves M, Conte G, Tian F, de Diego-Garcia L, Khalil M, Rosenow F, Delanty N, Dale N, El-Naggar H, Henshall DC, Engel T. Elevated blood purine levels as a biomarker of seizures and epilepsy. Epilepsia 2021; 62:817-828. [PMID: 33599287 DOI: 10.1111/epi.16839] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 12/30/2022]
Abstract
OBJECTIVE There is a major unmet need for a molecular biomarker of seizures or epilepsy that lends itself to fast, affordable detection in an easy-to-use point-of-care device. Purines such as adenosine triphosphate and adenosine are potent neuromodulators released during excessive neuronal activity that are also present in biofluids. Their biomarker potential for seizures and epilepsy in peripheral blood has, however, not yet been investigated. The aim of the present study was to determine whether blood purine nucleoside measurements can serve as a biomarker for the recent occurrence of seizures and to support the diagnosis of epilepsy. METHODS Blood purine concentrations were measured via a point-of-care diagnostic technology based on the summated electrochemical detection of adenosine and adenosine breakdown products (inosine, hypoxanthine, and xanthine; SMARTChip). Measurements of blood purine concentrations were carried out using samples from mice subjected to intra-amygdala kainic acid-induced status epilepticus and in video-electroencephalogram (EEG)-monitored adult patients with epilepsy. RESULTS In mice, blood purine concentrations were rapidly increased approximately two- to threefold after status epilepticus (2.32 ± .40 µmol·L-1 [control] vs. 8.93 ± 1.03 µmol·L-1 [after status epilepticus]), and levels correlated with seizure burden and postseizure neurodegeneration in the hippocampus. Blood purine concentrations were also elevated in patients with video-EEG-diagnosed epilepsy (2.39 ± .34 µmol·L-1 [control, n = 13] vs. 4.35 ± .38 µmol·L-1 [epilepsy, n = 26]). SIGNIFICANCE Our data provide proof of concept that the measurement of blood purine concentrations may offer a rapid, low-volume bedside test to support the diagnosis of seizures and epilepsy.
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Affiliation(s)
- Edward Beamer
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Austin Lacey
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Giorgia Conte
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Faming Tian
- Sarissa Biomedical, Coventry, UK.,School of Life Sciences, University of Warwick, Coventry, UK
| | - Laura de Diego-Garcia
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Mohamed Khalil
- Neurological Services, Beaumont Hospital, Dublin, Ireland
| | - Felix Rosenow
- Department of Neurology, Epilepsy Center Hessen, Marburg, Germany.,Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, University Hospital Frankfurt, LOEWE Center for Personalized Translational Epilepsy Research, Goethe University Frankfurt, Frankfurt on the Main, Germany
| | - Norman Delanty
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,Neurological Services, Beaumont Hospital, Dublin, Ireland
| | - Nicholas Dale
- Sarissa Biomedical, Coventry, UK.,School of Life Sciences, University of Warwick, Coventry, UK
| | - Hany El-Naggar
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,Neurological Services, Beaumont Hospital, Dublin, Ireland
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
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Real-time measurement of adenosine and ATP release in the central nervous system. Purinergic Signal 2020; 17:109-115. [PMID: 33025425 PMCID: PMC7954901 DOI: 10.1007/s11302-020-09733-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 09/13/2020] [Indexed: 11/12/2022] Open
Abstract
This brief review recounts how, stimulated by the work of Geoff Burnstock, I developed biosensors that allowed direct real-time measurement of ATP and adenosine during neural function. The initial impetus to create an adenosine biosensor came from trying to understand how ATP and adenosine-modulated motor pattern generation in the frog embryo spinal cord. Early biosensor measurements demonstrated slow accumulation of adenosine during motor activity. Subsequent application of these biosensors characterized real-time release of adenosine in in vitro models of brain ischaemia, and this line of work has recently led to clinical measurements of whole blood purine levels in patients undergoing carotid artery surgery or stroke. In parallel, the wish to understand the role of ATP signalling in the chemosensory regulation of breathing stimulated the development of ATP biosensors. This revealed that release of ATP from the chemosensory areas of the medulla oblongata preceded adaptive changes in breathing, triggered adaptive changes in breathing via activation of P2 receptors, and ultimately led to the discovery of connexin26 as a channel that mediates CO2-gated release of ATP from cells.
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Purines: From Diagnostic Biomarkers to Therapeutic Agents in Brain Injury. Neurosci Bull 2020; 36:1315-1326. [PMID: 32542580 DOI: 10.1007/s12264-020-00529-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
The purines constitute a family of inter-related compounds that serve a broad range of important intracellular and extracellular biological functions. In particular, adenosine triphosphate (ATP) and its metabolite and precursor, adenosine, regulate a wide variety of cellular and systems-level physiological processes extending from ATP acting as the cellular energy currency, to the adenosine arising from the depletion of cellular ATP and responding to reduce energy demand and hence to preserve ATP during times of metabolic stress. This inter-relationship provides opportunities for both the diagnosis of energy depletion during conditions such as stroke, and the replenishment of ATP after such events. In this review we address these opportunities and the broad potential of purines as diagnostics and restorative agents.
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Fisher O, Benson RA, Imray CH. The clinical application of purine nucleosides as biomarkers of tissue Ischemia and hypoxia in humans in vivo. Biomark Med 2019; 13:953-965. [PMID: 31321992 DOI: 10.2217/bmm-2019-0049] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During periods of ischemia and hypoxia, intracellular adenosine triphosphate stores are rapidly depleted. Its metabolism results in release of purine nucleosides into the systemic circulation. While the potential of purine nucleosides as a biomarker of ischemia has long been recognized, this has been limited by their complex physiological role and inherent instability leading to problematic sampling and prolonged, complex analysis procedures. Purine release has been demonstrated from cerebral tissue in patients undergoing carotid endarterectomy and patients presenting to hospital with stroke and transient ischemic attack. Rises in purine nucleosides have also been demonstrated in patients with angina and myocardial infarction, during systemic hypoxia, exercise, in patients with peripheral arterial disease and during surgery. This article reviews purine nucleoside production in ischemia, the development of purine analysis technology and details results of the studies investigating purine nucleosides as a biomarker of ischemia with suggestions for areas of future research.
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Affiliation(s)
- Owain Fisher
- Department of Vascular Surgery, University Hospital Coventry & Warwickshire, Coventry, CV2 2DX, UK.,Warwick Medical School, University of Warwick, CV4 7AL, UK
| | - Ruth A Benson
- Department of Vascular Surgery, University Hospital Coventry & Warwickshire, Coventry, CV2 2DX, UK.,Institute of Cancer & Genomic Sciences, University of Birmingham, B15 2SY, UK
| | - Christopher He Imray
- Department of Vascular Surgery, University Hospital Coventry & Warwickshire, Coventry, CV2 2DX, UK.,Warwick Medical School, University of Warwick, CV4 7AL, UK
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Fisher O, Benson RA, Tian F, Dale NE, Imray CH. Purine nucleoside use as surrogate markers of cerebral ischaemia during local and general anaesthetic carotid endarterectomy. SAGE Open Med 2019; 7:2050312119865120. [PMID: 31367381 PMCID: PMC6643180 DOI: 10.1177/2050312119865120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/01/2019] [Indexed: 12/02/2022] Open
Abstract
Objectives: In periods of cerebral ischaemia, adenosine triphosphate is metabolised,
leading to accumulation of adenosine inosine and hypoxanthine. These can be
measured in real time using peripheral blood samples intraoperatively. The
primary aim of this study was to describe changes in purine concentrations
in a cohort of patients undergoing carotid endarterectomy under general
anaesthetic, and to evaluate correlation between changes in values with
major perioperative steps. The secondary aim was to compare changes in
concentrations with a previous cohort of patients who had undergone carotid
endarterectomy under local anaesthetic. Methods: This was a prospective observational study. Purine concentrations were
determined from arterial line samples and measured via an amperometric
biosensor at specific time points during carotid endarterectomy. Mean
arterial pressure was manipulated to maintain steady cerebral perfusion
pressure throughout the procedure. These results were analysed against data
from a cohort of patients who underwent carotid endarterectomy under local
anaesthetic in previously published work. Results: Valid results were obtained for 37 patients. Purine concentrations at
baseline were 3.02 ± 1.11 µM and 3.16 ± 1.85 µM for the unshunted and
shunted cohorts, respectively. There was no significant change after 30 min
of carotid clamping at 2.07 ± 0.89 and 2.4 ± 3.09 µM, respectively (both p
> 0.05). Peak purine during the clamp phase in the loco-regional
anaesthetic cohort was 6.70 ± 3.4 µM, which was significantly raised
compared to both general anaesthetic cohorts (p = 0.004). There were no
perioperative neurological events in either cohort. Conclusion: This small study does not demonstrate conclusive evidence that purine
nucleosides can be used as a marker of cerebral ischaemia; the comparisons
to the loco-regional anaesthetic data offer information about differences in
the cerebral adenosine triphosphate metabolism between general anaesthetic
and loco-regional anaesthetic. We hypothesise that the lack of a rise in
purine nucleosides under general anaesthetic may be caused by a decrease in
the cerebral metabolic rate and loss of metabolic rate-blood flow coupling
caused by general anaesthetic agents.
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Affiliation(s)
- Owain Fisher
- Department of Vascular Surgery, University Hospitals Coventry and Warwickshire, Coventry, UK.,University of Warwick, Coventry, UK
| | - Ruth A Benson
- Department of Vascular Surgery, University Hospitals Coventry and Warwickshire, Coventry, UK.,University of Birmingham, Birmingham, UK
| | - Faming Tian
- University of Warwick, Coventry, UK.,Sarissa Biomedical Ltd, Coventry, UK
| | - Nicholas E Dale
- University of Warwick, Coventry, UK.,Sarissa Biomedical Ltd, Coventry, UK
| | - Christopher He Imray
- Department of Vascular Surgery, University Hospitals Coventry and Warwickshire, Coventry, UK.,University of Warwick, Coventry, UK
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Martin AJ, Dale N, Imray CHE, Roffe C, Smith CJ, Tian F, Price CI. The association between early neurological deterioration and whole blood purine concentration during acute stroke. Biomark Res 2019; 7:7. [PMID: 30988953 PMCID: PMC6448300 DOI: 10.1186/s40364-019-0158-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/27/2019] [Indexed: 11/10/2022] Open
Abstract
Background Early neurological deterioration (END) is common after stroke. Prediction could identify patients requiring additional monitoring and intervention. Purines, breakdown products of adenosine triphosphate which accumulate during acute hypoxia, may reflect the subclinical presence of vulnerable tissue. We considered whether whole blood purine concentration (WBPC) measurements during acute stroke were associated with subsequent END. Methods Patients within 4.5 h of stroke onset underwent point-of-care finger-prick measurement of WBPC and blinded assessment of symptom severity using the National Institutes of Health Stroke Scale (NIHSS). END was defined as an NIHSS increase ≥2 points at 24–36 h compared to baseline. Results 15/152 (9.8%) patients experienced END with a median [IQR] NIHSS increase of 4 [2–7] points. There were no strong associations between END and baseline NIHSS, clinical stroke subtype, thrombolytic therapy, physiological characteristics or time to assay. The median [IQR] WBPC concentration (uM) was higher before the occurrence of END but without statistical significance (7.21 [4.77–10.65] versus 4.83 [3.00–9.02]; p = 0.1). Above a WBPC threshold of 6.05uM, the risk of END was significantly greater (odds ratio 3.7 (95% CI 1.1–12.4); p = 0.03). Conclusion Although the study lacked statistical power, early WBPC measurement could be a convenient biomarker for identifying acute stroke patients at risk of END, but further evaluation is required.
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Affiliation(s)
- Alexander J Martin
- 1NIHR Newcastle Biomedical Research Centre and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Nicholas Dale
- 2School of Life Sciences, University of Warwick, Coventry, UK
| | - Christopher H E Imray
- Coventry and Warwickshire County Vascular Unit, University Hospitals Coventry and Warwickshire NHS Foundation Trust, Coventry, UK
| | - Christine Roffe
- 4Institute for Science and Technology in Medicine, University of Keele, Stoke-on-Trent, UK
| | - Craig J Smith
- 5Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | | | - Christopher I Price
- 1NIHR Newcastle Biomedical Research Centre and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.,Stroke Research Group, Newcastle University, Newcastle Upon Tyne, NE2 4AE UK
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Point-of-care measurements reveal release of purines into venous blood of stroke patients. Purinergic Signal 2019; 15:237-246. [PMID: 30859371 PMCID: PMC6635545 DOI: 10.1007/s11302-019-09647-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/31/2019] [Indexed: 11/10/2022] Open
Abstract
Stroke is a leading cause of death and disability. Here, we examine whether point-of-care measurement of the purines, adenosine, inosine and hypoxanthine, which are downstream metabolites of ATP, has potential to assist the diagnosis of stroke. In a prospective observational study, patients who were suspected of having had a stroke, within 4.5 h of symptom onset and still displaying focal neurological symptoms at admission, were recruited. Clinical research staff in the Emergency Departments of two hospitals used a prototype biosensor array, SMARTCap, to measure the purines in the venous blood of stroke patients and healthy controls. In controls, the baseline purines were 7.1 ± (SD) 4.2 μM (n = 52), while in stroke patients, they were 11.6 ± 8.9 μM (n = 76). Using the National Institutes for Stoke Scale (NIHSS) to band the severity of stroke, we found that minor, moderate and severe strokes all gave significant elevation of blood purines above the controls. The purine levels fall over 24 h. This was most marked for patients with haemorrhagic strokes (5.1 ± 3.6 μM, n = 9 after 24 h). The purine levels measured on admission show a significant correlation with the volume of affected brain tissue determined by medical imaging in patients who had not received thrombolysis or mechanical thrombectomy. ClinicalTrials.gov Identifier: NCT02308605
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Chatard C, Meiller A, Marinesco S. Microelectrode Biosensors forin vivoAnalysis of Brain Interstitial Fluid. ELECTROANAL 2018. [DOI: 10.1002/elan.201700836] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Charles Chatard
- INSERM U1028, CNRS UMR5292; Lyon Neuroscience Research Center, Team TIGER
- Université Claude Bernard Lyon 1; Lyon France
| | - Anne Meiller
- AniRA-Neurochem Technological Platform; Lyon France
- Université Claude Bernard Lyon 1; Lyon France
| | - Stéphane Marinesco
- INSERM U1028, CNRS UMR5292; Lyon Neuroscience Research Center, Team TIGER
- AniRA-Neurochem Technological Platform; Lyon France
- Université Claude Bernard Lyon 1; Lyon France
- Lyon Neuroscience Research Center, Team TIGER; Faculty of Medicine; 8 Avenue Rockefeller 69373 Lyon Cedex 08 France
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13
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Zhang L, Qi K. The Fabrication of an Amperometric Immunosensor Based on Double-Layer 2D-Network (3-Mercaptopropyl)trimethoxysilane Polymer and Platinum-Prussian Blue Hybrid Film. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20170266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lingyan Zhang
- Chongqing Institutions of Higher Learning Center of Forensic Science Engineering and Research, Southwest University of Political Science and Law, Chongqing 401120, P. R. China
| | - Kun Qi
- Chongqing Institutions of Higher Learning Center of Forensic Science Engineering and Research, Southwest University of Political Science and Law, Chongqing 401120, P. R. China
- Department of Law and Policy Research, Shanghai People’s Procuratorate, Shanghai 200020, P. R. China
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14
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Tian F, Bibi F, Dale N, Imray CHE. Blood purine measurements as a rapid real-time indicator of reversible brain ischaemia. Purinergic Signal 2017; 13:521-528. [PMID: 28803399 PMCID: PMC5714841 DOI: 10.1007/s11302-017-9578-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/02/2017] [Indexed: 12/12/2022] Open
Abstract
To preserve the disequilibrium between ATP and ADP necessary to drive cellular metabolism, enzymatic pathways rapidly convert ADP to adenosine and the downstream purines inosine and hypoxanthine. During ischaemia, these same pathways result in the production of purines. We performed a prospective observational study to test whether purine levels in arterial blood might correlate with brain ischaemia. We made real-time perioperative measurements, via microelectrode biosensors, of the purine levels in untreated arterial blood from 18 patients undergoing regional anaesthetic carotid endarterectomy. Pre-operatively, the median purine level was 2.4 μM (95% CI 1.3-4.0 μM); during the cross-clamp phase, the purines rose to 6.7 μM (95% CI 4.7-11.5 μM) and fell back to 1.9 μM (95% CI 1.4-2.7 μM) in recovery. Three patients became unconscious during carotid clamping, necessitating insertion of a temporary carotid shunt to restore cerebral blood flow. In these, the pre-operative median purine level was 5.4 μM (range 4.7-6.1 μM), on clamping, 9.6 μM (range 9.4-16.1 μM); during shunting, purines fell to below the pre-operative level (1.4 μM, range 0.4-2.9 μM) and in recovery 1.8 μM (range 1.8-2.6 μM). Our results suggest that blood purines may be a sensitive real-time and rapidly produced indicator of brain ischaemia, even when there is no accompanying neurological obtundation.
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Affiliation(s)
- Faming Tian
- Sarissa Biomedical Ltd., Vanguard Centre Sir William Lyons Road, Coventry, CV4 7EZ, UK
| | - Fakhra Bibi
- Sarissa Biomedical Ltd., Vanguard Centre Sir William Lyons Road, Coventry, CV4 7EZ, UK
| | - Nicholas Dale
- Sarissa Biomedical Ltd., Vanguard Centre Sir William Lyons Road, Coventry, CV4 7EZ, UK.
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
| | - Christopher H E Imray
- Department of Vascular Surgery, University Hospitals of Coventry and Warwickshire, Clifford Bridge Road, Coventry, UK
- Warwick Medical School, Coventry, CV4 7AL, UK
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15
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Palygin O, Evans LC, Cowley AW, Staruschenko A. Acute In Vivo Analysis of ATP Release in Rat Kidneys in Response to Changes of Renal Perfusion Pressure. J Am Heart Assoc 2017; 6:JAHA.117.006658. [PMID: 28899893 PMCID: PMC5634305 DOI: 10.1161/jaha.117.006658] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background ATP and derivatives are recognized to be essential agents of paracrine signaling. It was reported that ATP is an important regulator of the pressure‐natriuresis mechanism. Information on the sources of ATP, the mechanisms of its release, and its relationship to blood pressure has been limited by the inability to precisely measure dynamic changes in intrarenal ATP levels in vivo. Methods and Results Newly developed amperometric biosensors were used to assess alterations in cortical ATP concentrations in response to changes in renal perfusion pressure (RPP) in anesthetized Sprague–Dawley rats. RPP was monitored via the carotid artery; ligations around the celiac/superior mesenteric arteries and the distal aorta were used for manipulation of RPP. Biosensors were acutely implanted in the renal cortex for assessment of ATP. Rise of RPP activated diuresis/natriuresis processes, which were associated with elevated ATP. The increases in cortical ATP concentrations were in the physiological range (1–3 μmol/L) and would be capable of activating most of the purinergic receptors. There was a linear correlation with every 1‐mm Hg rise in RPP resulting in a 70‐nmol/L increase in ATP. Furthermore, this elevation of RPP was accompanied by a 2.5‐fold increase in urinary H2O2. Conclusions Changes in RPP directly correlate with renal sodium excretion and the elevation of cortical ATP. Given the known effects of ATP on regulation of glomerular filtration and tubular transport, the data support a role for ATP release in the rapid natriuretic responses to acute increases in RPP.
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
| | - Louise C Evans
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
| | - Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
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16
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A highly selective biosensor with nanomolar sensitivity based on cytokinin dehydrogenase. PLoS One 2014; 9:e90877. [PMID: 24595403 PMCID: PMC3942484 DOI: 10.1371/journal.pone.0090877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/03/2014] [Indexed: 11/19/2022] Open
Abstract
We have developed a N6-dimethylallyladenine (cytokinin) dehydrogenase-based microbiosensor for real-time determination of the family of hormones known as cytokinins. Cytokinin dehydrogenase from Zea mays (ZmCKX1) was immobilised concurrently with electrodeposition of a silica gel film on the surface of a Pt microelectrode, which was further functionalized by free electron mediator 2,6-dichlorophenolindophenol (DCPIP) in supporting electrolyte to give a bioactive film capable of selective oxidative cleavage of the N6- side chain of cytokinins. The rapid electron shuffling between freely diffusible DCPIP and the FAD redox group in ZmCKX1 endowed the microbiosensor with a fast response time of less than 10 s. The immobilised ZmCKX1 retained a high affinity for its preferred substrate N6-(Δ2-isopentenyl) adenine (iP), and gave the miniaturized biosensor a large linear dynamic range from 10 nM to 10 µM, a detection limit of 3.9 nM and a high sensitivity to iP of 603.3 µAmM-1cm-2 (n = 4, R2 = 0.9999). Excellent selectivity was displayed for several other aliphatic cytokinins and their ribosides, including N6-(Δ2-isopentenyl) adenine, N6-(Δ2-isopentenyl) adenosine, cis-zeatin, trans-zeatin and trans-zeatin riboside. Aromatic cytokinins and metabolites such as cytokinin glucosides were generally poor substrates. The microbiosensors exhibited excellent stability in terms of pH and long-term storage and have been used successfully to determine low nanomolar cytokinin concentrations in tomato xylem sap exudates.
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17
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Urbanova V, Kohring GW, Klein T, Wang Z, Mert O, Emrullahoglu M, Buran K, Demir AS, Etienne M, Walcarius A. Sol-gel Approaches for Elaboration of Polyol Dehydrogenase-Based Bioelectrodes. ACTA ACUST UNITED AC 2013. [DOI: 10.1524/zpch.2013.0324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Abstract
This review describes the input of sol-gel chemistry to the immobilization of polyol dehydrogenases on electrodes, for applications in bioelectrocatalysis. The polyol dehydrogenases are described and their application for biosensing, biofuel cell and electrosynthesis are briefly discussed. The immobilization of proteins via sol-gel approaches is described, including a discussion on the difficulty to maintain the activity of proteins in a silica matrix and the strategies developed to offer a proper environment to the proteins by developing optimal organic-inorganic hybrid materials. Finally, the co-immobilization of the NAD
+
co-factor and of mediators for the elaboration of reagentless devices is presented, based on published and original data. All-in-all, sol-gel approaches appear to be a very promising for development of original electrochemical applications involving dehydrogenases in near future.
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Affiliation(s)
- Veronika Urbanova
- CNRS and Université de Lorraine, Lab. de Chimie Physique et Microbiologie, Villers-les-Nancy, Frankreich
| | | | - Tobias Klein
- Saarland University, Microbiology, Saarbrücken, Deutschland
| | - Zhijie Wang
- CNRS and Université de Lorraine, Lab. de Chimie Physique et Microbiologie, Villers-les-Nancy, Frankreich
| | - Olcay Mert
- Middle East Technical University, Department of Chemistry, Ankara, Türkei
| | | | - Kerem Buran
- Middle East Technical University, Department of Chemistry, Ankara, Türkei
| | - Ayhan S. Demir
- Middle East Technical University, Department of Chemistry, Ankara, Türkei
| | | | - Alain Walcarius
- CNRS and Université de Lorraine, Lab. de Chemie Physique et Microbiologie, Villers-les-Nancy, Frankreich
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19
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Deng H, Shen W, Gao Z. An Interference-Free Glucose Biosensor Based on an Anionic Redox Polymer-Mediated Enzymatic Oxidation of Glucose. Chemphyschem 2013; 14:2343-7. [DOI: 10.1002/cphc.201200961] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Indexed: 11/11/2022]
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20
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Prussian Blue-modified ultramicroelectrodes for mapping hydrogen peroxide in scanning electrochemical microscopy (SECM). Electrochem commun 2012. [DOI: 10.1016/j.elecom.2012.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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21
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Tiwari I, Singh KP. Composite materials based on ormosil for the construction of electrochemical sensors and biosensors. RUSS J GEN CHEM+ 2012. [DOI: 10.1134/s1070363212010264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Wang Z, Etienne M, Pöller S, Schuhmann W, Kohring GW, Mamane V, Walcarius A. Dehydrogenase-Based Reagentless Biosensors: Electrochemically Assisted Deposition of Sol-Gel Thin Films on Functionalized Carbon Nanotubes. ELECTROANAL 2012. [DOI: 10.1002/elan.201100574] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Measurement of purine release with microelectrode biosensors. Purinergic Signal 2011; 8:27-40. [PMID: 22095158 DOI: 10.1007/s11302-011-9273-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 09/19/2011] [Indexed: 12/22/2022] Open
Abstract
Purinergic signalling departs from traditional paradigms of neurotransmission in the variety of release mechanisms and routes of production of extracellular ATP and adenosine. Direct real-time measurements of these purinergic agents have been of great value in understanding the functional roles of this signalling system in a number of diverse contexts. Here, we review the methods for measuring purine release, introduce the concept of microelectrode biosensors for ATP and adenosine and explain how these have been used to provide new mechanistic insight in respiratory chemoreception, synaptic physiology, eye development and purine salvage. We finish by considering the association of purine release with pathological conditions and examine the possibilities that biosensors for purines may one day be a standard part of the clinical diagnostic tool chest.
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Chen W, Cai S, Ren QQ, Wen W, Zhao YD. Recent advances in electrochemical sensing for hydrogen peroxide: a review. Analyst 2011; 137:49-58. [PMID: 22081036 DOI: 10.1039/c1an15738h] [Citation(s) in RCA: 525] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Due to the significance of hydrogen peroxide (H(2)O(2)) in biological systems and its practical applications, the development of efficient electrochemical H(2)O(2) sensors holds a special attraction for researchers. Various materials such as Prussian blue (PB), heme proteins, carbon nanotubes (CNTs) and transition metals have been applied to the construction of H(2)O(2) sensors. In this article, the electrocatalytic H(2)O(2) determinations are mainly focused on because they can provide a superior sensing performance over non-electrocatalytic ones. The synergetic effect between nanotechnology and electrochemical H(2)O(2) determination is also highlighted in various aspects. In addition, some recent progress for in vivo H(2)O(2) measurements is also presented. Finally, the future prospects for more efficient H(2)O(2) sensing are discussed.
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Affiliation(s)
- Wei Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
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25
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Kowalska M, Tian F, Šmehilová M, Galuszka P, Frébort I, Napier R, Dale N. Prussian Blue acts as a mediator in a reagentless cytokinin biosensor. Anal Chim Acta 2011; 701:218-23. [PMID: 21801891 DOI: 10.1016/j.aca.2011.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 04/19/2011] [Accepted: 06/15/2011] [Indexed: 10/18/2022]
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26
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Perry M, Li Q, Kennedy RT. Review of recent advances in analytical techniques for the determination of neurotransmitters. Anal Chim Acta 2009; 653:1-22. [PMID: 19800472 PMCID: PMC2759352 DOI: 10.1016/j.aca.2009.08.038] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/25/2009] [Accepted: 08/27/2009] [Indexed: 12/18/2022]
Abstract
Methods and advances for monitoring neurotransmitters in vivo or for tissue analysis of neurotransmitters over the last five years are reviewed. The review is organized primarily by neurotransmitter type. Transmitter and related compounds may be monitored by either in vivo sampling coupled to analytical methods or implanted sensors. Sampling is primarily performed using microdialysis, but low-flow push-pull perfusion may offer advantages of spatial resolution while minimizing the tissue disruption associated with higher flow rates. Analytical techniques coupled to these sampling methods include liquid chromatography, capillary electrophoresis, enzyme assays, sensors, and mass spectrometry. Methods for the detection of amino acid, monoamine, neuropeptide, acetylcholine, nucleoside, and soluble gas neurotransmitters have been developed and improved upon. Advances in the speed and sensitivity of these methods have enabled improvements in temporal resolution and increased the number of compounds detectable. Similar advances have enabled improved detection at tissue samples, with a substantial emphasis on single cell and other small samples. Sensors provide excellent temporal and spatial resolution for in vivo monitoring. Advances in application to catecholamines, indoleamines, and amino acids have been prominent. Improvements in stability, sensitivity, and selectivity of the sensors have been of paramount interest.
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Affiliation(s)
- Maura Perry
- University of Michigan, Department of Chemistry, 930 N. University, Ann Arbor, MI 48109-1055, USA
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27
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Tian F, Gourine AV, Huckstepp RTR, Dale N. A microelectrode biosensor for real time monitoring of L-glutamate release. Anal Chim Acta 2009; 645:86-91. [PMID: 19481635 DOI: 10.1016/j.aca.2009.04.048] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 02/19/2009] [Accepted: 04/29/2009] [Indexed: 01/12/2023]
Abstract
We have developed an amperometric microbiosensor for real time monitoring L-glutamate release in neural tissue, based on enzymatic oxidation catalyzed by the L-glutamate oxidase. By means of a sol-gel coating method, L-glutamate oxidase was entrapped in a biocompatible gel layer that provided a benign environment and retained enzyme activity on the surface of Pt microelectrode. Prior to gel layer formation, a modification on the surface of Pt microelectrode with poly(phenylene diamine) enabled the microbiosensor screen majority of common potential interfering substances existing in physiological samples. The miniaturized biosensor achieved a steady state response to l-glutamate within 10 s and exhibited a linear dependence on the concentration of L-glutamate from 0.5 to 100 micromol L(-1) with a high sensitivity of 279.4 +/- 2.0 microA (mmol L(-1))(-1) cm(-2) (n = 4, R.S.D. = 2.8%). The microbiosensor also exhibited excellent long-term stability in dry storage. We have successfully used the microbiosensor for real time measuring of L-glutamate in vivo.
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Affiliation(s)
- Faming Tian
- Warwick Biosensors Group, Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom.
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28
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Paixão T, Bertotti M. Ruthenium Oxide Hexacyanoferrate Modified Electrode for Hydrogen Peroxide Detection. ELECTROANAL 2008. [DOI: 10.1002/elan.200804231] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Affiliation(s)
- Benjamin J Privett
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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30
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Das J, Patra S, Yang H. Enhancement of the electrocatalytic activity of gold nanoparticles via NaBH4 treatment. Chem Commun (Camb) 2008:4451-3. [DOI: 10.1039/b806984k] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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