1
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Sicchieri LB, Monteiro AM, Figueiredo Neto AM, Gomes L, Courrol LC. Optical Properties of Europium Tetracycline Complexes in the Presence of High-Density Lipoproteins (HDL) Subfractions. APPLIED SPECTROSCOPY 2017; 71:1560-1567. [PMID: 27956595 DOI: 10.1177/0003702816683685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Standard lipoprotein measurements of triglycerides, total cholesterol, low-density lipoproteins (LDL), and high-density lipoproteins (HDL) fail to identify many lipoprotein abnormalities that contribute to cardiovascular heart diseases (CHD). Studies suggested that the presence of CHD is more strongly associated with the HDL subspecies than with total HDL cholesterol levels. The HDL particles can be collected in at least three subfractions, the HDL2b, HDL2a, and HDL3. More specifically, atherosclerosis is associated with low levels of HDL2. In this work, the optical spectroscopic properties of europium tetracycline (EuTc) complex in the presence of different HDL subspecies was studied. The results show that the europium spectroscopic properties in the EuTc complex are influenced by sizes and concentrations of subclasses. Eu3+ emission intensity and lifetime can discriminate the subfractions HDL3 and HDL2b.
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Affiliation(s)
| | | | | | - Laércio Gomes
- 1 Centro de Lasers e Aplicações, IPEN/CNEN, São Paulo, SP, Brazil
| | - Lilia Coronato Courrol
- 1 Centro de Lasers e Aplicações, IPEN/CNEN, São Paulo, SP, Brazil
- 3 Depto de Ciências Exatas e da Terra, Universidade Federal de São Paulo (Brazil), Diadema, SP, Brazil
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2
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Ma HR, Peng HS, You FT, Ping JT, Zhou C, Guo LY. Sensitive detection of PDT-induced cell damages with luminescent oxygen nanosensors. Methods Appl Fluoresc 2016; 4:035001. [DOI: 10.1088/2050-6120/4/3/035001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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3
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Terai T, Ito H, Hanaoka K, Komatsu T, Ueno T, Nagano T, Urano Y. Detection of NAD(P)H-dependent enzyme activity by time-domain ratiometry of terbium luminescence. Bioorg Med Chem Lett 2016; 26:2314-7. [PMID: 27013390 DOI: 10.1016/j.bmcl.2016.03.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/09/2016] [Accepted: 03/11/2016] [Indexed: 10/22/2022]
Abstract
NAD(P)H-dependent oxidoreductases play important roles in biology. Recently, we reported that the luminescence lifetime of some Tb(3+) complexes is sensitive to NAD(P)H, and we used this phenomenon to detect activities of these enzymes. However, conventional time-resolved luminescence assays are susceptible to static quenchers such as ATP. Herein we describe a detection methodology that overcomes this issue: the intensity of the sample is measured twice with different delay times and the intensity ratio value is used as an index of NAD(P)H concentration. The method is more robust than single-point measurement, and is compatible with high-throughput assays using conventional microplate readers.
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Affiliation(s)
- Takuya Terai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; AMED CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
| | - Hiroki Ito
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; AMED CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Kenjiro Hanaoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toru Komatsu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; JST PRESTO, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Tasuku Ueno
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; AMED CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Tetsuo Nagano
- Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuteru Urano
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; AMED CREST, 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan; Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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4
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Meier RJ, Simbürger JMB, Soukka T, Schäferling M. A FRET based pH probe with a broad working range applicable to referenced ratiometric dual wavelength and luminescence lifetime read out. Chem Commun (Camb) 2015; 51:6145-8. [PMID: 25747771 DOI: 10.1039/c5cc00144g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A luminescent probe for determination of pH was designed based on a Förster resonance energy transfer (FRET) system, combining a europium chelate as the donor and carboxynaphtho-fluorescein as a pH sensitive acceptor. The FRET system enables referenced pH detection in an exceptional broad dynamic range from pH 3 to 9.
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Affiliation(s)
- Robert J Meier
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
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5
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Żamojć K, Zdrowowicz M, Jacewicz D, Wyrzykowski D, Chmurzyński L. Fluorescent Probes Used for Detection of Hydrogen Peroxide under Biological Conditions. Crit Rev Anal Chem 2015; 46:171-200. [DOI: 10.1080/10408347.2015.1014085] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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6
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Hamilton GRC, Sheng Y, Callan B, Donnelly RF, Callan JF. A hydrogel based zinc(ii) sensor for use in fluorescent multi-well plate analysis. NEW J CHEM 2015. [DOI: 10.1039/c5nj00259a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A polymeric hydrogel sensor for zinc has been developed for use in fluorescence multi-well plate assay.
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Affiliation(s)
- Graham R. C. Hamilton
- School of Pharmacy and Pharmaceutical Sciences
- The University of Ulster
- Northern Ireland
| | - Yingjie Sheng
- School of Pharmacy and Pharmaceutical Sciences
- The University of Ulster
- Northern Ireland
| | - Bridgeen Callan
- School of Pharmacy and Pharmaceutical Sciences
- The University of Ulster
- Northern Ireland
| | | | - John F Callan
- School of Pharmacy and Pharmaceutical Sciences
- The University of Ulster
- Northern Ireland
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7
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Martínez-Olmos A, Fernández-Salmerón J, Lopez-Ruiz N, Rivadeneyra Torres A, Capitan-Vallvey LF, Palma AJ. Screen Printed Flexible Radiofrequency Identification Tag for Oxygen Monitoring. Anal Chem 2013; 85:11098-105. [DOI: 10.1021/ac4028802] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Martínez-Olmos
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
| | - J. Fernández-Salmerón
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
| | - N. Lopez-Ruiz
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
| | - A. Rivadeneyra Torres
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
| | - L. F. Capitan-Vallvey
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
| | - A. J. Palma
- ECsens, Department of Electronics and Computer
Technology and ‡Department of Analytical Chemistry, Campus Fuentenueva, Faculty of
Sciences, University of Granada, E-18071 Granada, Spain
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8
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9
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Schäferling M. The Art of Fluorescence Imaging with Chemical Sensors. Angew Chem Int Ed Engl 2012; 51:3532-54. [PMID: 22422626 DOI: 10.1002/anie.201105459] [Citation(s) in RCA: 443] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/12/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Michael Schäferling
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany.
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10
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Murillo Pulgarín JA, Alañón Molina A, Martínez Ferreras F. Simultaneous determination of nabumetone and its principal metabolite in medicines and human urine by time-resolved fluorescence. Analyst 2012; 137:5144-52. [DOI: 10.1039/c2an35412h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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12
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Vilozny B, Schiller A, Wessling RA, Singaram B. Multiwell plates loaded with fluorescent hydrogel sensors for measuring pH and glucose concentration. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm04257a] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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14
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Moczko E, Meglinski IV, Bessant C, Piletsky SA. Dyes assay for measuring physicochemical parameters. Anal Chem 2010; 81:2311-6. [PMID: 19220044 DOI: 10.1021/ac802482h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of selective fluorescent dyes has been developed for simultaneous quantitative measurements of several physicochemical parameters. The operating principle of the assay is similar to electronic nose and tongue systems, which combine nonspecific or semispecific elements for the determination of diverse analytes and chemometric techniques for multivariate data analysis. The analytical capability of the proposed mixture is engendered by changes in fluorescence signal in response to changes in environment such as pH, temperature, ionic strength, and presence of oxygen. The signal is detected by a three-dimensional spectrofluorimeter, and the acquired data are processed using an artificial neural network (ANN) for multivariate calibration. The fluorescence spectrum of a solution of selected dyes allows discreet reading of emission maxima of all dyes composing the mixture. The variations in peaks intensities caused by environmental changes provide distinctive fluorescence patterns which can be handled in the same way as the signals collected from nose/tongue electrochemical or piezoelectric devices. This optical system opens possibilities for rapid, inexpensive, real-time detection of a multitude of physicochemical parameters and analytes of complex samples.
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Affiliation(s)
- Ewa Moczko
- Cranfield Health, Cranfield University, Cranfield, MK43 0AL, UK.
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15
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Payne SJ, Demas JN, Degraff BA. Abnormal behavior in Stern-Volmer luminescence quenching measurements via apparent lifetime methods. APPLIED SPECTROSCOPY 2009; 63:437-441. [PMID: 19366510 DOI: 10.1366/000370209787944307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Luminescence lifetimes are widely used as an analysis tool. Since decays in analytical systems are frequently complex decays rather than single exponentials, apparent lifetime methods based on the rapid lifetime determination (RLD) method or single frequency phase shift (SFPS) measurements are frequently used to reduce cost and simplify data analysis. It is demonstrated here that these methods can produce large errors under the right conditions. Both methods can give unexpected and uncharacteristic Stern-Volmer quenching plots (SVQPs) in two-component systems. Behaviors include bimodal quenching curves as well as "anti-quenching" curves. These phenomena are exacerbated by small fractions of long unquenched components.
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Affiliation(s)
- Sarah J Payne
- Chemistry Department, University of Virginia, Charlottesville, Virginia 22904, USA
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16
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De Oliveira Silva FR, Monteiro AM, Neto AMF, Gidlund M, Junior NDV, Courrol LC. Analytical quantification of low-density lipoprotein using europium tetracycline indicator. LUMINESCENCE 2009; 24:189-93. [PMID: 19291808 DOI: 10.1002/bio.1094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Low-density lipoprotein (LDL) is known as 'bad' cholesterol. If too much LDL circulates in the blood it can be retained in the walls of the arteries, causing atherosclerosis. In this paper we showed an alternative method to quantify LDL using the europium tetracycline (EuTc) indicator. The optical properties of the EuTc complex were investigated in aqueous solutions containing LDL. An enhancement was observed of the europium luminescence in the solutions with LDL compared those without the lipoprotein. A method to quantify the amount of LDL in a sample, based on EuTc enhanced luminescence, is proposed. The enhancement mechanism is also discussed.
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17
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Optical Properties of Metacycline, Oxytetracycline and Chlortetracycline Europium Complexes in the Presence of Hydrogen Peroxide. J Fluoresc 2009; 19:715-21. [DOI: 10.1007/s10895-009-0465-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Accepted: 01/16/2009] [Indexed: 11/26/2022]
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18
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Kostov Y, Sergeev N, Wilson S, Herold KE, Rasooly A. A simple portable electroluminescence illumination-based CCD detector. Methods Mol Biol 2009; 503:259-72. [PMID: 19151946 DOI: 10.1007/978-1-60327-567-5_14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this chapter we describe a simple and relatively inexpensive Electroluminescence (EL) illumination and charged-coupled device (CCD) camera (EL-CCD) based detector for monitoring fluorescence and colorimetric assays. The portable battery-operated fluorescence detector includes an EL panel for fluoro-genic excitation at 490 nm, a cooled CCD digital camera to monitor emission at 523 nm, filters and a close up lens. The detector system is controlled by a laptop computer for camera operation, image acquisition and analysis. The system was tested using a fluorogenic peptide substrate (SNAP-25) for botulinum neurotoxin serotype A (BoNT-A) labeled with FITC. The level of detection of the system was found to be 1.25 nM of the peptide, similar to the detection level of a commercial photomultipler-based plate fluorometer. The multichannel EL-CCD was used with an assay plate capable of testing nine samples simultaneously in 1 min at this detection level. The portable system is small and is operated by a 12 V source. The modular detector was designed with easily interchangeable ELs, filters and lenses and can be used and adapted for a wide variety of fluorescence and colorimetric assays, fluorescence labels and assay formats.
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Affiliation(s)
- Yordan Kostov
- Center for Advanced Sensor Technology, University of Maryland Baltimore County, Baltimore, MD, USA
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19
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Nagl S, Stich MIJ, Schäferling M, Wolfbeis OS. Method for simultaneous luminescence sensing of two species using optical probes of different decay time, and its application to an enzymatic reaction at varying temperature. Anal Bioanal Chem 2008; 393:1199-207. [PMID: 18998117 DOI: 10.1007/s00216-008-2467-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 10/07/2008] [Accepted: 10/08/2008] [Indexed: 11/30/2022]
Abstract
Chemical sensing, imaging and microscopy based on the use of fluorescent probes has so far been limited almost exclusively to the detection of a single parameter at a time. We present a scheme that can overcome this limitation by enabling optical sensing of two parameter simultaneously and even at identical excitation and emission wavelengths of two probes provided (a) their decay times are different enough to enable two time windows to be recorded, and (b) the emission of the shorter-lived probe decays to below the detectable limit while that of the other still can be measured. We refer to this new scheme as the dual lifetime determination (DLD) method and show that it can be widely varied by appropriate choice of probes and experimental settings. DLD is demonstrated to work by sensing oxygen and temperature independently from each other by making use of two probes, one for oxygen (a platinum porphyrin dissolved in polystyrene), and one for temperature [a europium complex dissolved in poly(vinyl methylketone)]. DLD was applied to monitor the consumption of oxygen in the glucose oxidase-catalyzed oxidation of glucose at varying temperatures. The scheme is expected to have further applications in cellular assays and biophysical imaging.
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Affiliation(s)
- Stefan Nagl
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040, Regensburg, Germany
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20
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Spangler CM, Spangler C, Schäerling M. Luminescent lanthanide complexes as probes for the determination of enzyme activities. Ann N Y Acad Sci 2008; 1130:138-48. [PMID: 18596342 DOI: 10.1196/annals.1430.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The determination of enzyme activities and the screening of enzyme regulators is a major task in clinical chemistry and the development of new drugs. A broad variety of enzymatic reactions is associated with the consumption or formation of small molecules like H(2)O(2), ATP, pyrophosphate, or phosphate. Luminescent lanthanide complexes can be applied to monitor these enzymatic conversions and therefore can serve as probes for the determination of enzyme activities. The utility of this concept will be demonstrated by means of some selected examples including europium and terbium complexes. Accordingly, this new approach could be already implemented for the determination of glucose oxidase, catalase, and peroxidase activity. In particular, enzymes that catalyze phosphorylation or dephosphorylation reactions came to the fore of interest because of their high relevance as drug targets. These include (protein) kinases, adenylyl cyclases, phosphodiesterases, phosphatases, and ATPases. The development and design of fluorescent lanthanide complexes should lead to probes with optimized selectivity and response times that can be applied for high-throughput screening of enzyme inhibitors and for real-time monitoring of enzyme kinetics. In contrast to other assays for enzyme activity determination, this method does not require the use of radioactively labelled substrates or the accomplishment of rather complex and expensive immunoassays.
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Affiliation(s)
- Corinna M Spangler
- Institute for Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany
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21
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Fluorescence Sensing and Imaging Using Pressure-Sensitive Paints and Temperature-Sensitive Paints. STANDARDIZATION AND QUALITY ASSURANCE IN FLUORESCENCE MEASUREMENTS I 2008. [DOI: 10.1007/4243_2008_025] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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22
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Intrinsically Referenced Fluorimetric Sensing and Detection Schemes: Methods, Advantages and Applications. STANDARDIZATION AND QUALITY ASSURANCE IN FLUORESCENCE MEASUREMENTS I 2008. [DOI: 10.1007/4243_2008_023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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23
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Schäferling M, Wolfbeis OS. Europium tetracycline as a luminescent probe for nucleoside phosphates and its application to the determination of kinase activity. Chemistry 2007; 13:4342-9. [PMID: 17323391 DOI: 10.1002/chem.200601509] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The determination of enzyme activities and the screening of enzyme regulators is a major task in clinical chemistry and drug development. A broad variety of enzymatic reactions is associated with the consumption of adenosine triphosphate (ATP), including, in particular, phosphorylation reactions catalyzed by kinases, formation of adenosine cyclic monophosphate (cAMP) by adenylate cyclases, and ATP decomposition by ATPase. We have studied the effect of a series of adenosine (ATP, ADP, AMP, cAMP) and guanosine (GTP, GDP) phosphoric esters, and of pyrophosphate (PP) on the fluorescence emission of the europium tetracycline (EuTC) complex. We found that these compounds have strongly different quenching effects on the luminescence emission of EuTC. The triphosphates ATP and GTP behave as strong quenchers in reducing the fluorescence intensity of EuTC to 25 % of its initial value by formation of a ternary 1:1:1 complex. All other phosphate esters showed a weak quenching effect only. The applicability of this fluorescent probe to the determination of the activity of phosphorylation enzymes is demonstrated by means of creatine kinase as a model for non-membrane-bound kinases. In contrast to other methods, this approach does not require the use of radioactively labeled ATP substrates, additional enzymes, or of rather complex immunoassays.
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Affiliation(s)
- Michael Schäferling
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany.
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24
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Mills A, Tommons C, Bailey RT, Tedford MC, Crilly PJ. Reversible, fluorescence-based optical sensor for hydrogen peroxide. Analyst 2007; 132:566-71. [PMID: 17525814 DOI: 10.1039/b618506a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The preparation and characterisation are described of a robust, reversible, hydrogen peroxide optical sensor, based on the fluorescent quenching of the dye ion-pair [Ru(bpy)(3)(2+)(Ph(4)B(-))(2)], by O(2) produced by the catalytic breakdown of H(2)O(2), utilizing the inorganic catalyst RuO(2).xH(2)O. The main feature of this system is the one-pot formulation of a coating ink that, when dried, forms an active single-layer fluorescence-based H(2)O(2) sensor, demonstrably capable of detecting H(2)O(2) over the range of 0.01 to 1 M, with a relative standard deviation of ca. 4% and a calculated lower limit of detection of 0.1 mM. These sensors are sterilisable, using dry-heat, and stable when stored over 40 days, without exhibiting any loss in sensitivity or response characteristics.
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Affiliation(s)
- Andrew Mills
- WestCHEM, Department of Pure & Applied Chemistry, University of Strathclyde, Thomas Graham Building, Glasgow, UK.
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25
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New Plastic Microparticles and Nanoparticles for Fluorescent Sensing and Encoding. SPRINGER SERIES ON FLUORESCENCE 2007. [DOI: 10.1007/4243_2007_013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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26
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Lin Z, Wu M, Wolfbeis OS, Schäferling M. A Novel Method for Time-Resolved Fluorimetric Determination and Imaging of the Activity of Peroxidase, and Its Application to an Enzyme-Linked Immunosorbent Assay. Chemistry 2006; 12:2730-8. [PMID: 16416495 DOI: 10.1002/chem.200500884] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A new type of fluorescence assay for the determination of peroxidase (POx) activity is presented. The assay is based on the indication of the enzymatic consumption of H(2)O(2) (HP), using a fluorescent europium-tetracycline (Eu(3)TC) complex as indicator. On addition of HP, this complex forms a highly fluorescent adduct (Eu(3)TC-HP), which is decomposed in the presence of POx to form the weakly fluorescent europium-tetracycline (Eu(3)TC). Hence, the activity of the enzyme can be directly determined by means of the luminescent Eu(3)TC complex as indicator. The POx assay demonstrated herein was elaborated starting from a spectral characterization of the complex systems involved. Due to the long lifetime of lanthanide luminescence, both steady-state and time-resolved luminescence assays can easily be performed. The time-resolved assay can quantify POx in the range from 4.0 x 10(-5) to 5.9 x 10(-3) U mL(-1), with a limit of detection of 1.0 x 10(-5) U mL(-1). The effects of POx inhibitors such as cyanide, hydroxylamine, and azide have also been studied. In addition, a time-resolved fluorescent detection method for a POx-based enzyme-linked immunosorbent assay (ELISA) has been developed, which is demonstrated in a sandwich model assay with bovine IgG serving as analyte. Furthermore, a time-resolved fluorescent imaging method is demonstrated that makes use of a straightforward imaging set-up adjusted to the optical properties of the europium reagent.
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Affiliation(s)
- Zhihong Lin
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
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27
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Cano-Raya C, Fernádez Ramos MD, Capitán Vallvey LF, Wolfbeis OS, Schäferling M. Fluorescence quenching of the europium tetracycline hydrogen peroxide complex by copper (II) and other metal ions. APPLIED SPECTROSCOPY 2005; 59:1209-1216. [PMID: 18028617 DOI: 10.1366/000370205774430945] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The europium-tetracycline complex [Eu(Tc)] is known to show only weak fluorescence with an emission maximum at 615 nm. On addition of hydrogen peroxide (HP), the strongly fluorescent [Eu(Tc)(HP)] complex is formed, which displays a 15-fold stronger luminescence intensity. This study describes the decrease in luminescence intensity of the [Eu(Tc)(HP)] complex in aqueous solution in the presence of Cu2+, Fe3+, Ag+, Al3+, Zn2+, Co2+, Ni2+, Mn2+, Ca2+, and Mg2+. Static and dynamic quenching can be induced by Cu2+, and these processes were quantified by means of their quenching constants. Stern-Volmer plots were also derived from lifetime imaging measurements accomplished by the rapid lifetime determination (RLD) technique based on microwell plate assays, and also by the time-correlated single photon counting (TCSPC) technique. According to those data, a time-resolved fluorescent method for copper determination can be proposed that is based on dynamic quenching of the [Eu(Tc)(HP)] complex by Cu2+ ions. The response to copper concentrations is linear up to 1.6 micromol L(-1), providing a detection limit of 0.2 micromol L(-1).
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Affiliation(s)
- Clara Cano-Raya
- Department of Analytical Chemistry, University of Granada, Granada 18071, Spain
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Wu M, Lin Z, Schäferling M, Dürkop A, Wolfbeis OS. Fluorescence imaging of the activity of glucose oxidase using a hydrogen-peroxide-sensitive europium probe. Anal Biochem 2005; 340:66-73. [PMID: 15802131 DOI: 10.1016/j.ab.2005.01.050] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Indexed: 11/30/2022]
Abstract
A method for optical imaging of the activity of glucose oxidase (GOx) using a fluorescent europium(III) tetracycline probe for hydrogen peroxide is presented. A decay time in the microsecond range and the large Stokes shift of 210 nm of the probe facilitate intensity-based, time-resolved, and decay-time-based imaging of glucose oxidase. Four methods for imaging the activity of GOx were compared, and rapid lifetime determination imaging was found to be the best in giving a linear range from 0.32 to 2.7 m Unit/mL. The detection limit is 0.32 m Unit/mL (1.7 ng mL(-1)) which is similar to that of the time-resolved (gated) imaging using a microtiterplate reader. Fluorescent imaging of the activity of GOx is considered to be a useful tool for GOx-based immunoassays with potential for high-throughput screening, immobilization studies, and biosensor array technologies.
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Affiliation(s)
- Meng Wu
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany
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Babilas P, Liebsch G, Schacht V, Klimant I, Wolfbeis OS, Szeimies RM, Abels C. In Vivo Phosphorescence Imaging ofpO2Using Planar Oxygen Sensors. Microcirculation 2005; 12:477-87. [PMID: 16147465 DOI: 10.1080/10739680591003314] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Oxygen-dependent quenching of luminescence of metal porphyrin complexes has been used to image the pO(2) distribution over tumor and normal tissue. METHODS An experimental setup is described using a platinum(II)-octaethyl-porphyrin immobilized in a polystyrene matrix as transparent planar sensor. RESULTS Sensitivity over a broad range is high at low pO(2) values (+/- 0.2 mm Hg at 0 mm Hg; +/- 1.5 mm Hg at 160 mm Hg pO(2)). Due to intrinsically referencing via lifetime encoding there was no modification of the sensor response in vivo in the dorsal skinfold chamber model with amelanotic melanoma (A-MEL-3) in awake hamsters when compared to the in vitro calibration. pO(2) measurements over normal tissue (25.8 +/- 5.1 mm Hg) and tumor tissue (9.2 +/- 5.1 mm Hg) were in excellent agreement with previous results obtained in this model using a surface multiwire electrode. CONCLUSIONS Using the presented method the surface pO(2) distribution can be mapped with a high temporal resolution of approximately 100 ms and a spatial resolution of at least 25 mu m. Moreover, the transparent sensor allows the simultaneous visualization of the underlying microvasculature.
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Affiliation(s)
- Philipp Babilas
- Department of Dermatology, University of Regensburg, Germany.
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Lin Z, Wu M, Wolfbeis OS. Time-resolved fluorescent chirality sensing and imaging of malate in aqueous solution. Chirality 2005; 17:464-9. [PMID: 16104025 DOI: 10.1002/chir.20185] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chiral discrimination of malates in aqueous solutions at near-neutral pH is achieved through fluorescence measurement and imaging using the europium-tetracycline complex (EuTc) as a fluorescent probe. The method is based on the significantly different fluorescence properties of the ternary complexes (Eu-Tc-malate) formed between EuTc and the enantiomeric malates. The enantiomeric excess (ee) of chiral malates can be quantified by both steady-state and time-resolved fluorescence, using either a conventional fluorescence microplate reader or fluorescence imaging. It offers a facile and sensitive method for high-throughput chiral discrimination.
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Affiliation(s)
- Zhihong Lin
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, Regensburg, Germany
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Wu M, Lin Z, Dürkop A, Wolfbeis OS. Time-resolved enzymatic determination of glucose using a fluorescent europium probe for hydrogen peroxide. Anal Bioanal Chem 2004; 380:619-26. [PMID: 15480582 DOI: 10.1007/s00216-004-2785-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2004] [Revised: 07/19/2004] [Accepted: 07/26/2004] [Indexed: 10/26/2022]
Abstract
An enzymatic assay for glucose based on the use of the fluorescent probe for hydrogen peroxide, europium(III) tetracycline (EuTc), is described. The weakly fluorescent EuTc and enzymatically generated H2O2 form a strongly fluorescent complex (EuTc-H2O2) whose fluorescence decay profile is significantly different. Since the decay time of EuTc-H2O2 is in the microseconds time domain, fluorescence can be detected in the time-resolved mode, thus enabling substantial reduction of background fluorescence. The scheme represents the first H2O2-based time-resolved fluorescence assay for glucose not requiring the presence of a peroxidase. The time-resolved assay (with a delay time of 60 micros and using endpoint detection) enables glucose to be determined at levels as low as 2.2 micromol L(-1), with a dynamic range of 2.2-100 micromol L(-1). The method also was adapted to a kinetic assay in order to cover higher glucose levels (mmol L(-1) range). The latter was validated by analyzing spiked serum samples and gave a good linear relationship for glucose levels from 2.5 to 55.5 mmol L(-1). Noteworthy features of the assay include easy accessibility of the probe, large Stokes' shift, a line-like fluorescence peaking at 616 nm, stability towards oxygen, a working pH of approximately 7, and its suitability for both kinetic and endpoint determination.
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Affiliation(s)
- Meng Wu
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
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Affiliation(s)
- Otto S Wolfbeis
- Institute of Analytical Chemistry, University of Regensburg, D-93040 Regensburg, Germany
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