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Priyadarshini E, Minzar M, Pandey S, Rawat K. Biocompatible gelatin/carbon dot nanocomposite based urea sensor and the effect of nitrogen ion implantation. Biochem Biophys Res Commun 2023; 675:99-105. [PMID: 37463525 DOI: 10.1016/j.bbrc.2023.06.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/07/2023] [Accepted: 06/26/2023] [Indexed: 07/20/2023]
Abstract
In this study, we have fabricated a novel platform for sensing of urea using gelatin/carbon dots nanocomposite system. The sensor electrode was created by depositing the nanocomposite gel onto thin glass plates coated with indium tin oxide (ITO) using the drop casting technique. The behavior of these electrodes was investigated against a number of bioanalytes in the concentration range of 2-20 mM by cyclic voltammetry. The system was observed to be highly selective for urea with a sensitivity of 1.65 μA/mM/cm in the experimental linear range of 2-20 mM. Furthermore, the gelatin/CD-ITO electrode were also subjected to 50 KeV N2+ ion beam irradiation with varying fluence in the range of 1012 to 1016 ions/cm2. Sensing profile of the irradiated samples for urea suggested enhancement in sensitivity to 2 μA/mM cm2, when the ion fluence was 5 × 1015 ions/cm2. This enhancement after irradiation suggests a clear dependence of detection on the fluence of the ion beam. The observed excellent sensitivity of radiation processed nanocomposite material can be used as an enzyme-free platform for urea detection. Additionally, the CDs showed fluorescence quenching on treatment with mere 50 μM urea suggesting the high sensitivity of the platform.
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Affiliation(s)
| | - Mohd Minzar
- Department of Chemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India
| | - Saurabh Pandey
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
| | - Kamla Rawat
- Department of Chemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
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Narimani R, Esmaeili M, Rasta SH, Khosroshahi HT, Mobed A. Trend in creatinine determining methods: Conventional methods to molecular‐based methods. ANALYTICAL SCIENCE ADVANCES 2021; 2:308-325. [DOI: 10.1002/ansa.202000074] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/28/2020] [Indexed: 10/07/2023]
Abstract
AbstractRenal failure (RF) disease is ranked as one of the most prevalent diseases with severe morbidity and mortality. Early diagnosis of RF leads to subsequent control of disease to reduce the poor prognosis. The level of sera creatinine is considered as a significant biomarker for kidney biofunction, which is routinely detected by the Jaffe reaction. The normal range for creatinine in the blood may be 0.84‐1.21 mg/dL. Low accuracy, insufficient sensitivity, explosive and toxicity of picric acid, and pseudo‐interaction with nonspecific elements such as ammonium ions in the Jaffe method lead to the development of various techniques for precise detection of creatinine such as spectroscopic, electrochemical, and chromatography approaches and sensors based on enzymes, molecular imprinted polymer and nanoparticles, etc. Based on previously established results, they are trying to construct sensors with high accuracy, optimum sensitivity, acceptable linear/calibration range, and limit of detection, which are small in size and applicable by the patient him/herself (point‐of‐care testing). By comparing the results of research, a molecularly imprinted electrochemiluminescence‐based sensor with linear/calibration range of 5‐1 mMconcentration of creatinine and the detection limit of 0.5 nM has the best detectable resolution with 2 million measurable points. In this paper, we will review the recently developed methods for measuring creatinine concentration and renal biofunction.
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Affiliation(s)
- Ramin Narimani
- Medical Bioengineering Department, School of Advanced Medical Sciences Tabriz University of Medical Sciences Tabriz Iran
- Molecular Medicine Research Center Tabriz University of Medical Sciences Tabriz Iran
| | - Mahdad Esmaeili
- Medical Bioengineering Department, School of Advanced Medical Sciences Tabriz University of Medical Sciences Tabriz Iran
| | - Seyed Hossein Rasta
- Medical Bioengineering Department, School of Advanced Medical Sciences Tabriz University of Medical Sciences Tabriz Iran
- Department of Medical Physics, School of Medicine Tabriz University of Medical Sciences Tabriz Iran
- Department of Biomedical Physics, School of Medical Sciences University of Aberdeen Aberdeen UK
| | - Hamid Tayebi Khosroshahi
- Center for Chronic Kidney Disease Tabriz University of Medical Sciences Tabriz Iran
- Department of Internal Medicine, Imam Reza Hospital Tabriz University of Medical Sciences Tabriz Iran
- Biotechnology Research Center Tabriz University of Medical Sciences Tabriz Iran
| | - Ahmad Mobed
- Aging Research Institute Tabriz University of Medical Sciences Tabriz Iran
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Qu F, Chen Y, Jiang D, Zhao XE. pH-modulated aggregation-induced emission of Au/Cu nanoclusters and its application to the determination of urea and dissolved ammonia. Mikrochim Acta 2021; 188:113. [PMID: 33677619 DOI: 10.1007/s00604-021-04770-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/20/2021] [Indexed: 01/11/2023]
Abstract
A fluorescence platform is designed based on aggregation-induced emission of Au/Cu nanoclusters (Au/Cu NCs) driven by pH value. When pH increases from 6.0 to 7.0, Au/Cu NCs change from aggregation to dispersion, accompanied by the oxidation of Cu cores. Under the catalysis of urease, urea is hydrolysed to release ammonia, which further undergoes a hydrolysis reaction to produce OH-, causing the pH to increase. The fluorescence of Au/Cu NCs quenches linearly at 590 nm with the excitation wavelength at 320 nm when the concentration of urea varies from 5.0 to 100 μM. The limit of detection (LOD) and limit of quantification (LOQ) of urea are 2.23 and 7.45 μM, respectively. Combined with headspace single-drop microextraction technology, Au/Cu NCs are employed to monitor dissolved ammonia with low-cost and simple operation. The linear range of dissolved ammonia is from 20 to 300 μM. The LOD and LOQ of dissolved ammonia are 7.04 and 23.4 μM, respectively. The relative standard deviation (RSD) values of the intra-day and inter-day precision of urea are 2.4-3.0% and 3.0-3.7%, respectively, and those of dissolved ammonia are in the range 3.4-5.1% (intra-day precision) and 4.2-5.8% (inter-day precision). No interferences have been indentified in the determination of urea and dissolved ammonia. Finally, the proposed method has been applied to determine urea in human urine samples and dissolved ammonia in water samples with satisfactory results.Graphical abstract The pH increase produces the dispersion and decomposition of Au/Cu NCs, leading to the fluorescence quenching. Both urea and dissolved ammonia are detected successfully because they cause the pH change to alkaline.
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Affiliation(s)
- Fei Qu
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu, 273165, Shandong, China. .,The Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu, 273165, Shandong, China.
| | - Yanan Chen
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu, 273165, Shandong, China.,The Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Dafeng Jiang
- Department of Physical and Chemical Testing, Shandong Center for Disease Control and Prevention, Jinan, 250014, China
| | - Xian-En Zhao
- The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu, 273165, Shandong, China. .,The Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu, 273165, Shandong, China.
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Uzunçar S, Meng L, Turner AP, Mak WC. Processable and nanofibrous polyaniline:polystyrene-sulphonate (nano-PANI:PSS) for the fabrication of catalyst-free ammonium sensors and enzyme-coupled urea biosensors. Biosens Bioelectron 2021; 171:112725. [DOI: 10.1016/j.bios.2020.112725] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/28/2020] [Accepted: 10/12/2020] [Indexed: 12/15/2022]
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Flow-based method for the determination of biomarkers urea and ammoniacal nitrogen in saliva. Bioanalysis 2020; 12:455-465. [DOI: 10.4155/bio-2020-0036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: Salivary urea and ammonium levels are potential biomarkers for chronic kidney disease. A fast and efficient assessment of these compounds in the saliva of healthy and diseased individuals may be a useful tool to monitor kidney function. Materials & methods: Ammonium ions were measured with an ammonia selective electrode after conversion to ammonia gas. A urease reactor was incorporated in the manifold to hydrolyze urea to ammonium, thereby providing values of ammonia from both urea and ammonium ions in the sample. The accuracy of the method was assessed by comparison with a commercially available kit for urea and ammonium determination. Conclusion: A sequential injection method for the biparametric determination of salivary urea and ammonium employing a single sequential injection manifold was successfully applied to samples collected from both healthy volunteers and chronic kidney disease patients.
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Pundir CS, Jakhar S, Narwal V. Determination of urea with special emphasis on biosensors: A review. Biosens Bioelectron 2018; 123:36-50. [PMID: 30308420 DOI: 10.1016/j.bios.2018.09.067] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/09/2018] [Accepted: 09/19/2018] [Indexed: 11/24/2022]
Abstract
Urea is the major end product of nitrogen metabolism in humans, which is eliminated from the body mainly by the kidneys through urine but is also secreted in body fluids such as blood and saliva. Its level in urine ranges from 7 to 20 mg/dL, which drastically rises under patho-physiological conditions thus providing key information of renal function and diagnosis of various kidney and liver disorders. Increase in urea levels in blood, also referred to as azotemia or uremia. The chronic kidney disease (CKD) or end stage renal disease (ESRD) is generally caused due to the progressive loss of kidney function. Hence, there is an urgent need of determination of urea in biological fluids to diagnose these diseases at their early stage. Among the various methods available for detection of urea, most are complicated and require time-consuming sample pre-treatment, expensive instrumental set-up and trained persons to operate, specifically for chromatographic methods. The biosensing methods overcome these drawbacks, as these are simple, fast, specific and highly sensitive and can also be applied for detection of urea in vivo. This review presents the principles of various analytical methods for determination of urea with special emphasis on biosensors. The use of various nanostructures and electrochemical microfluidic paper based analytical device (EμPAD) are suggested for further development of urea biosensors.
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Affiliation(s)
- C S Pundir
- Department of Biochemistry, M.D. University, Rohtak 124001, Haryana, India.
| | - Seema Jakhar
- Department of Biochemistry, M.D. University, Rohtak 124001, Haryana, India
| | - Vinay Narwal
- Department of Biochemistry, M.D. University, Rohtak 124001, Haryana, India
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Jakhar S, Pundir C. Preparation, characterization and application of urease nanoparticles for construction of an improved potentiometric urea biosensor. Biosens Bioelectron 2018; 100:242-250. [DOI: 10.1016/j.bios.2017.09.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 10/18/2022]
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8
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Toledo PRAB, Toci AT, Pezza HR, Pezza L. Green Determination of Urea in Moisturizers by Diffuse Reflectance Spectroscopy. ANAL LETT 2017. [DOI: 10.1080/00032719.2016.1255223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Aline Theodoro Toci
- Latin American Institute of Science of Life and Nature, Federal University of Latin American Integration – UNILA, Paraná, Brazil
| | | | - Leonardo Pezza
- Institute of Chemistry, São Paulo State University – UNESP, São Paulo, Brazil
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Zhybak M, Beni V, Vagin M, Dempsey E, Turner A, Korpan Y. Creatinine and urea biosensors based on a novel ammonium ion-selective copper-polyaniline nano-composite. Biosens Bioelectron 2016; 77:505-11. [DOI: 10.1016/j.bios.2015.10.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/29/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022]
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11
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Pawlak M, Bakker E. Chemical Modification of Polymer Ion-Selective Membrane Electrode Surfaces. ELECTROANAL 2014. [DOI: 10.1002/elan.201300449] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Shu HC, Wu NP. Continuous Analysis of Urea in Blood by Immobilized Urease Using a Conductive Biosensor. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200000137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Determining urea levels in dialysis human serum by means of headspace solid phase microextraction coupled with ion mobility spectrometry and on the basis of nanostructured polypyrrole film. Anal Bioanal Chem 2013; 405:5333-9. [DOI: 10.1007/s00216-013-6912-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 03/06/2013] [Accepted: 03/08/2013] [Indexed: 10/27/2022]
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14
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Iridium oxide pH sensor for biomedical applications. Case urea–urease in real urine samples. Biosens Bioelectron 2013; 39:163-9. [DOI: 10.1016/j.bios.2012.07.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 07/13/2012] [Indexed: 11/21/2022]
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Nabati F, Habibi-Rezaei M, Amanlou M, Moosavi-Movahedi A. Dioxane enhanced immobilization of urease on alkyl modified nano-porous silica using reversible denaturation approach. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcatb.2011.01.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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16
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Dual potentiometric and UV/Vis spectrophotometric disposable sensors with dispersion cast polyaniline. J Solid State Electrochem 2010. [DOI: 10.1007/s10008-010-1073-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Catalytic systems based on the organic nickel(ii) complexes in chronoamperometric determination of urea and creatinine. Russ Chem Bull 2010. [DOI: 10.1007/s11172-009-0145-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Syu MJ, Chang YS. Ionic effect investigation of a potentiometric sensor for urea and surface morphology observation of entrapped urease/polypyrrole matrix. Biosens Bioelectron 2009; 24:2671-7. [DOI: 10.1016/j.bios.2009.01.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 01/23/2009] [Accepted: 01/23/2009] [Indexed: 10/21/2022]
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20
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Xu Y, Bakker E. Ion channel mimetic chronopotentiometric polymeric membrane ion sensor for surface-confined protein detection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:568-573. [PMID: 19067579 PMCID: PMC2664528 DOI: 10.1021/la802728p] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The operation of ion channel sensors is mimicked with functionalized polymeric membrane electrodes, using a surface confined affinity reaction to impede the electrochemically imposed ion transfer kinetics of a marker ion. A membrane surface biotinylated by covalent attachment to the polymeric backbone is used here to bind to the protein avidin as a model system. The results indicate that the protein accumulates on the ion-selective membrane surface, partially blocking the current-induced ion transfer across the membrane/aqueous sample interface, and subsequently decreases the potential jump in the so-called super-Nernstian step that is characteristic of a surface depletion of the marker ion. The findings suggest that such a potential drop could be utilized to measure the concentration of protein in the sample. Because the sensitivity of protein sensing is dependent on the effective blocking of the active surface area, it can be improved with a hydrophilic nanopore membrane applied on top of the biotinylated ion-selective membrane surface. On the basis of cyclic voltammetry characterization, the nanoporous membrane electrodes can indeed be understood as a recessed nanoelectrode array. The results show that the measuring range for protein sensing on nanopore electrodes is shifted to lower concentrations by more than 1 order of magnitude, which is explained with the reduction of surface area by the nanopore membrane and the related more effective hemispherical diffusion pattern.
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Affiliation(s)
- Yida Xu
- Department of Chemistry, Purdue University, Indiana 47907, USA
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Voltammetric Detection of Urea on an Ag-Modified Zeolite-Expanded Graphite-Epoxy Composite Electrode. SENSORS 2008; 8:5806-5819. [PMID: 27873841 PMCID: PMC3705531 DOI: 10.3390/s8095806] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2008] [Revised: 09/13/2008] [Accepted: 09/18/2008] [Indexed: 11/17/2022]
Abstract
In this paper, a modified expanded graphite composite electrode based on natural zeolitic volcanic tuff modified with silver (EG-Ag-Z-Epoxy) was developed. Cyclic voltammetry measurements revealed a reasonably fast electron transfer and a good stability of the electrode in 0.1 M NaOH supporting electrolyte. This modified electrode exhibited moderate electrocatalytic effect towards urea oxidation, allowing its determination in aqueous solution. The linear dependence of the current versus urea concentration was reached using square-wave voltammetry in the concentrations range of urea between 0.2 to 1.4 mM, with a relatively low limit of detection of 0.05 mM. A moderate enhancement of electroanalytical sensitivity for the determination of urea at EG-Ag-Z-Epoxy electrode was reached by applying a chemical preconcentration step prior to voltammetric/amperometric quantification.
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Correia DPA, Magalhães JMCS, Machado AASC. Array of potentiometric sensors for multicomponent analysis of blood serum. Mikrochim Acta 2008. [DOI: 10.1007/s00604-007-0920-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Koncki R. Recent developments in potentiometric biosensors for biomedical analysis. Anal Chim Acta 2007; 599:7-15. [PMID: 17765058 DOI: 10.1016/j.aca.2007.08.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 07/30/2007] [Accepted: 08/02/2007] [Indexed: 11/18/2022]
Abstract
A large variety of potentiometric biosensors is developed using biocatalytic and bioaffinity-based biosensing schemes. However, only few of them could be applied for the biomedical analysis. The most promising are those for the detection of main products of protein metabolism, namely urea and creatinine. A novel group of potentiometric biosensors is constituted by bioaffinity-based devices that could be used for immunoassays or genoanalysis. This paper reviews the recent trends in these fields as well as discusses advantages, limitations and pitfalls of the developed biosensors. Some potentiometric biosensors useful for real biomedical analysis are reported in detail.
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Affiliation(s)
- Robert Koncki
- University of Warsaw, Department of Chemistry, Pasteura 1, 02-093 Warsaw, Poland.
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Abstract
A review based on 94 cited original papers describes recent achievements in application of different electrochemical detection in flow analysis, injection techniques of flow analysis, liquid chromatography and capillary electrophoresis.
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Affiliation(s)
- Marek Trojanowicz
- Laboratory for Flow Analysis and Chromatography, Department of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland.
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25
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Ma A, Rosenzweig Z. Synthesis and analytical properties of micrometric biosensing lipobeads. Anal Bioanal Chem 2005; 382:28-36. [PMID: 15900448 DOI: 10.1007/s00216-005-3186-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Revised: 02/14/2005] [Accepted: 02/15/2005] [Indexed: 11/29/2022]
Abstract
This paper describes the preparation for the first time of lipobead-based micrometric fluorescence biosensors and the optimization of their analytical properties. The study focused on the well-established urea biosensors as a model system. Fluorescence-sensing lipobeads were prepared by coating carboxyl-functionalized silica microspheres with phospholipids. The enzyme urease and the pH indicator fluorescein-5-thiosemicarbazide were then attached covalently to the phospholipid membrane of the lipobeads. Urease converts urea to ammonia, which results in a pH increase in the analyte solution and to a urea concentration-dependent increase in the fluorescence intensity of the sensing lipobeads. Previous fluorescence-sensing lipobeads were synthesized by coating polystyrene particles with a phospholipid membrane. The membrane was physically attached to the particles and the fluorophores were entrapped in the membrane. In this study, we prepared improved fluorescence-sensing lipobeads by utilizing covalent chemistry to bind the phospholipid membrane to the silica particles and the fluorophores to the membrane. This led to improvement in the stability of the newly developed urea-sensing lipobeads compared to previously developed miniaturized fluorescence biosensors.
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Affiliation(s)
- Aihui Ma
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA
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26
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Radomska A, Bodenszac E, Głąb S, Koncki R. Creatinine biosensor based on ammonium ion selective electrode and its application in flow-injection analysis. Talanta 2004; 64:603-8. [DOI: 10.1016/j.talanta.2004.03.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2003] [Revised: 02/23/2004] [Accepted: 03/22/2004] [Indexed: 11/17/2022]
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27
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Luo YC, Do JS. Urea biosensor based on PANi(urease)-Nafion®/Au composite electrode. Biosens Bioelectron 2004; 20:15-23. [PMID: 15142572 DOI: 10.1016/j.bios.2003.11.028] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Accepted: 11/21/2003] [Indexed: 11/28/2022]
Abstract
The polyaniline (PANi)-Nafion composite film was prepared onto the ceramic plate by the cyclic voltammetry (CV) method with the various cycle numbers. When the PANi-Nafion/Au/ceramic plate with the preparing cycle number of 5 was as working electrode, the cathodic peak current was achieved as 84.0 microA in 60 mg dl(-1) NH4Cl buffer solution. On the other hand, the small cathodic peak currents for buffer solution in the presence of 60 mg dl(-1) LiOH, NaCl and KCl, respectively, were found with the same composite electrode as working electrode. The cathodic peak current decreased from 84.0 to 16.3 microA in the 60 mg dl(-1) NH4Cl buffer solution when the cycle number for preparing PANi-Nafion/Au/ceramic plate composite electrode with the CV method increased from 5 to 15. The enzyme of urease was immobilized onto the PANi-Nafion/Au/ceramic plate composite film by the electrochemical immobilization and the casting methods and used as sensing electrode to detect the concentration of urea in the buffer solution. The sensitivity of composite electrode immobilized with the casting method was greater than that of electrochemical immobilization method. The sensitivity and the detecting limit of the urea sensor were found to be 0.7 and 5.27 microA (mg dl(-1))(-1)cm(-2), as well as 6 and 0.3 mg dl(-1), respectively, when urease was immobilized by glutaraldehyde (GA) cross-linker and Nafion network, respectively.
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Affiliation(s)
- Yung-Chien Luo
- Department of Chemical Engineering, Tunghai University, Taichung 40704, Taiwan, ROC
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28
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Trojanowicz M, Szewczynska M, Wcislo M. Electroanalytical Flow Measurements-Recent Advances. ELECTROANAL 2003. [DOI: 10.1002/elan.200390041] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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29
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Abstract
An optical biosensor for urea measurements was developed. The operation of the sensor is based on the well-known urease enzyme-catalyzed hydrolysis of urea. The ammonium ions liberated in the reaction are detected with an ion selective optode membrane containing nonactin as ion selective ionophore and ETH 5294 chromoionophore in a thin (1 microm) plasticized poly(vinylchloride) film. The basic sensing element was home made of a microscope glass slide, a HeNe laser light source, photodiode light detector and light in coupling, de-coupling elements. The transducer membrane and the enzyme containing reaction layer were sandwich-cast with spin coating onto the surface of the sensing slide. The attenuation of the laser light propagating inside the glass wave-guide was used as signal for urea measurements. With this arrangement membranes provided good sensitivity (0.05 absorption unit when going from 0.1 to 1 mM urea) and short (16-20 s) response time. Taking advantage on the improved response time, flow injection urea measurements were made in the 0.01-2 mM concentration range. Thirty sample/hour analysis-rate, good peak-to-peak reproducibility (RSD=0.02) and recovery (95-104%) was achieved with buffer diluted urea solutions. Applications for the analysis of real samples are planned to do in the future.
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Affiliation(s)
- Barna Kovács
- Department for General and Physical Chemistry, University of Pécs, 7624 Pécs, Ifjúság u. 6, Hungary
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Kleinbongard P, Rassaf T, Dejam A, Kerber S, Kelm M. Griess method for nitrite measurement of aqueous and protein-containing samples. Methods Enzymol 2003; 359:158-68. [PMID: 12481568 DOI: 10.1016/s0076-6879(02)59180-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Petra Kleinbongard
- Department of Medicine, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
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Koncki R, Radomska A, Głąb S. Bioanalytical flow-injection system for control of hemodialysis adequacy. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00961-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Liu CH, Liao KT, Huang HJ. Amperometric immunosensors based on protein A coupled polyaniline-perfluorosulfonated ionomer composite electrodes. Anal Chem 2000; 72:2925-9. [PMID: 10905329 DOI: 10.1021/ac9914317] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A very sensitive immunosensor based on polyaniline/ Nafion/protein A (PA/NF/PrA) composite electrodes has been developed for the amperometric immunoanalysis with urease-labeled immunoreagents. The use of urease conjugated goat anti-RIgG (GaRIgG-Ur) as the labeled antibody and urea as the substrate with an amperometric detection at -200 mV (vs Ag/AgCl) resulted in a dynamic range of 50-2000 ng mL-1 and a low detection limit of 10 ng/mL (64 pM) for the immunoanalysis of rabbit immunoglobulin G (RIgG). Because of the special affinity between protein A and RIgG, the PA/NF/PrA electrode can be regenerated repetitively by changing the pH of the buffer solutions. Characteristics of the PA/NF/PrA/RIgG immunosensor and optimal conditions for the competitive immunoanalysis of RIgG with FIA were studied.
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Affiliation(s)
- C H Liu
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
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Schulz K, Kerber S, Kelm M. Reevaluation of the Griess method for determining NO/NO2- in aqueous and protein-containing samples. Nitric Oxide 1999; 3:225-34. [PMID: 10442854 DOI: 10.1006/niox.1999.0226] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) is an important intracellular and extracellular signal substance. Nitrite is one product of the oxidative metabolism of NO. The purpose of this study was to establish a simple method of determining nitrite (NO2-) to provide a means of estimating the endogenous formation of NO or NO2-. A flow injection analysis (FIA) based on the Griess reaction was developed for this purpose. Using a standard additive method, it is possible to eliminate matrix effects such as those that can occur in samples containing protein. This measuring method is suitable for measurements in effluates or protein-rich cellular supernatants. The sensitivity of the method is 2 nmol/L for samples in aqueous phases and 8 nmol/L for protein-containing phases. The two-point discrimination is 2 nmol/L. A linear correlation between nitrite and signal level can be demonstrated over a range of 0.002-5 micromol/L. Reproducibility, including sample preparation and analysis, can be specified with a coefficient of variation (C.V.) of 6.7%. Day-to-day variability for identical samples 0.8% (C.V.). This study presents examples of the application of this method (measurements in blood samples and in isolated perfused hearts) and compares them to established methods of measuring NO and NO2. We found the FIA method to be equally sensitive as NO measurement by means of oxyhemoglobin assay. The FIA method is seven times more sensitive than HPLC methods, and its design is significantly simpler. Compared to the traditional Griess method, its sensitivity is higher by a factor of 500. With its high sensitivity, high reproducibility, and its unsurpassed low susceptibility to interference, this method of analysis provides a means of reliably determining nitrite concentration as a marker of NO formation in various matrices. Therefore, it can be a valuable instrument in experimental and clinical studies to determine the physiologic and pathophysiologic relevance of NO.
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Affiliation(s)
- K Schulz
- Department of Medicine, Heinrich-Heine-University, Duesseldorf, Germany
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