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Gauthier-Manuel B, Benmouhoub C, Wacogne B. Fluorescence Spectra of Prototropic Forms of Fluorescein and Some Derivatives and Their Potential Use for Calibration-Free pH Sensing. SENSORS (BASEL, SWITZERLAND) 2024; 24:1705. [PMID: 38475241 DOI: 10.3390/s24051705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024]
Abstract
Fluorescence pH sensing has proven to be efficient but with the drawback that molecules photobleach, requiring frequent calibrations. Double-emission peak molecules allow ratiometric measurements and theoretically avoid calibration. However, they are often expensive and fragile and usually have very low quantum yields. Single emission peaks such as fluorescein and derivatives are inexpensive and have very high quantum yields. Because they are single emission peaks, the pH is assumed to be derived from the ratio of emitted intensities at measured pH and at high pH values, i.e., they require frequent calibration. However, the shape of their single emitted peak evolves slightly with pH. In this paper, we first demonstrate a simple method to calculate the emission spectrum shape of each prototropic form of fluorescein (and derivatives) as well as the values of the pKas. A complete model of the evolution of the emission spectrum shape with pH is then constructed. Second, we evaluate the potential of these molecules for pH sensing by fitting the experimental spectra with the complete emission model. The method is applied to fluorescein, FITC and FAM. Depending on the molecule, pH can be measured from pH 1.9 to pH 7.3 with standard deviations between 0.06 and 0.08 pH units. Estimating pH and pKas from shape instead of intensity allows calibration-free measurements even with single-emission peak molecules.
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Affiliation(s)
| | - Chafia Benmouhoub
- CNRS, Institut FEMTO-ST, Université de Franche-Comté, 25000 Besançon, France
- SATT Grand Est, SAYENS, 25000 Besançon, France
| | - Bruno Wacogne
- CNRS, Institut FEMTO-ST, Université de Franche-Comté, 25000 Besançon, France
- INSERM CIC 1431, Besançon University Hospital, 25030 Besançon, France
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2
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Seemann KM, Kiefersauer R, Jacob U, Kuhn B. Optical pH Detection within a Protein Crystal. J Phys Chem B 2012; 116:9873-81. [DOI: 10.1021/jp2103512] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Klaus M. Seemann
- Peter Grünberg Institute, Research Center Jülich, 52425 Jülich,
Germany
| | | | - Uwe Jacob
- Westend-Innovation GmbH, 80339 München, Germany
| | - Bernd Kuhn
- Department of Membrane and Neurophysics, Max Planck Institute of Biochemistry, 82152 Martinsried,
Germany
- Optical Neuroimaging
Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa 904-0412, Japan
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Chen YC, Ostafin A, Mizukami H. Synthesis and characterization of pH sensitive carboxySNARF-1 nanoreactors. NANOTECHNOLOGY 2010; 21:215503. [PMID: 20431200 DOI: 10.1088/0957-4484/21/21/215503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A rapid response dual wavelength emission pH sensor consisting of carboxySNARF-1 nanoreactors has been synthesized and shown to provide accurate pH measurements even in complex biological media, where the unprotected pH responsive dyes have failed. The carboxySNARF-1 nanoreactor is made of a calcium phosphate shell covering phosphatidylcholine liposomes filled with the dye. Its mean diameter is 150 nm with dynamic light scattering, the shell thickness is 5-7 nm with TEM, and it contains about 10 dyes/particle. The nanoreactor's response time to pH change nearly equals that of the dye in solution. Its pH titration curves at two different wavelengths are equivalent to those of the dye in solution and fluorescence intensity ratio dependent pH analysis is possible using the modified Henderson-Hasselbalch equation. However, the pH dependent fluorescence ratios of the dye in solution in the presence of plasma and albumin are distorted, and application of the Henderson-Hasselbalch equation is not possible. We have found that the distortions may be restored using cSNARF-1 nanoreactors and the pK(a) of the dye in the nanoreactor then equals that in solution. These results suggest that the interference to the dye for the pH analyses with the environmental molecules may be reduced or prohibited by usage of cSNARF-1 nanoreactors.
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Affiliation(s)
- Yen-Chi Chen
- Department of Materials Science, University of Utah, Salt Lake City, UT, USA
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4
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Zhao H, Huang C, Wu L, Shen S, Qin Z. Resonance Light Scattering Method to Determine Binding Ratio and Functional Affinity Constant of Antigen/Antibody Immunoreaction. ANAL LETT 2009. [DOI: 10.1080/00032710902961099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Večeř J, Holoubek A, Sigler K. Fluorescence Behavior of the pH-Sensitive Probe Carboxy SNARF-1 in Suspension of Liposomes¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2001)0740008fbotps2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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6
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Rojas JD, Sennoune SR, Maiti D, Bakunts K, Reuveni M, Sanka SC, Martinez GM, Seftor EA, Meininger CJ, Wu G, Wesson DE, Hendrix MJC, Martínez-Zaguilán R. Vacuolar-type H+-ATPases at the plasma membrane regulate pH and cell migration in microvascular endothelial cells. Am J Physiol Heart Circ Physiol 2006; 291:H1147-57. [PMID: 16679513 DOI: 10.1152/ajpheart.00166.2006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microvascular endothelial cells involved in angiogenesis are exposed to an acidic environment that is not conducive for growth and survival. These cells must exhibit a dynamic intracellular (cytosolic) pH (pHcyt) regulatory mechanism to cope with acidosis, in addition to the ubiquitous Na+/H+exchanger and HCO3−-based H+-transporting systems. We hypothesize that the presence of plasmalemmal vacuolar-type proton ATPases (pmV-ATPases) allows microvascular endothelial cells to better cope with this acidic environment and that pmV-ATPases are required for cell migration. This study indicates that microvascular endothelial cells, which are more migratory than macrovascular endothelial cells, express pmV-ATPases. Spectral imaging microscopy indicates a more alkaline pHcytat the leading than at the lagging edge of microvascular endothelial cells. Treatment of microvascular endothelial cells with V-ATPase inhibitors decreases the proton fluxes via pmV-ATPases and cell migration. These data suggest that pmV-ATPases are essential for pHcytregulation and cell migration in microvascular endothelial cells.
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Affiliation(s)
- J D Rojas
- Department of Physiology, Texas Tech University Health Sciences Center, 3601 4th St., Lubbock, TX 79430-6551, USA
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7
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Sánchez-Armáss S, Sennoune SR, Maiti D, Ortega F, Martínez-Zaguilán R. Spectral imaging microscopy demonstrates cytoplasmic pH oscillations in glial cells. Am J Physiol Cell Physiol 2005; 290:C524-38. [PMID: 16135543 DOI: 10.1152/ajpcell.00290.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glial cells exhibit distinct cellular domains, somata, and filopodia. Thus the cytoplasmic pH (pH(cyt)) and/or the behavior of the fluorescent ion indicator might be different in these cellular domains because of distinct microenvironments. To address these issues, we loaded C6 glial cells with carboxyseminaphthorhodafluor (SNARF)-1 and evaluated pH(cyt) using spectral imaging microscopy. This approach allowed us to study pH(cyt) in discrete cellular domains with high temporal, spatial, and spectral resolution. Because there are differences in the cell microenvironment that may affect the behavior of SNARF-1, we performed in situ titrations in discrete cellular regions of single cells encompassing the somata and filopodia. The in situ titration parameters apparent acid-base dissociation constant (pK'(a)), maximum ratio (R(max)), and minimum ratio (R(min)) had a mean coefficient of variation approximately six times greater than those measured in vitro. Therefore, the individual in situ titration parameters obtained from specific cellular domains were used to estimate the pH(cyt) of each region. These studies indicated that glial cells exhibit pH(cyt) heterogeneities and pH(cyt) oscillations in both the absence and presence of physiological HCO(3)(-). The amplitude and frequency of the pH(cyt) oscillations were affected by alkalosis, by acidosis, and by inhibitors of the ubiquitous Na(+)/H(+) exchanger- and HCO(3)(-)-based H(+)-transporting mechanisms. Optical imaging approaches used in conjunction with BCECF as a pH probe corroborated the existence of pH(cyt) oscillations in glial cells.
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Affiliation(s)
- Sergio Sánchez-Armáss
- Departamento de Fisiología y Farmacología, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
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Yang R, Li K, Liu F, Li N, Zhao F, Chan W. 3,3‘,5,5‘-Tetramethyl-N-(9-anthrylmethyl)benzidine: A Dual-Signaling Fluorescent Reagent for Optical Sensing of Aliphatic Aldehydes. Anal Chem 2003; 75:3908-14. [PMID: 14572061 DOI: 10.1021/ac020789r] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new optical chemical sensor for continuous monitoring of aliphatic aldehydes has been proposed based on the reversible chemical reaction between a new sensing reagent, 3,3',5,5'-tetramethyl-N-(9-anthrylmethyl)benzidine (TMAB), and the analytes. TMAB, containing two receptors and two fluorescent reporters, can perform dual fluorescence responses corresponding to the reactions of hydrogen ion and carbonyl compound. When immobilized in a plasticized poly(vinyl chloride) membrane, TMAB extracts aliphatic aldehydes from aqueous solution into the bulk membrane phase and reacts with the analyte by forming a Schiff base. Since the extraction equilibrium and chemical reaction are accompanied by fluorescence increase of the sensing membrane, the chemical recognition process could be directly translated into an optical signal. At pH 3.20, the sensor exhibits a dynamic detection range from 0.017 to 4.2 mM n-butyraldehyde with a limit of detection of 0.003 mM. The forward response time (t95) of the sensor is 3-5 min, and the reverse response time is 5-7 min. The responses of the sensor toward different kinds of aldehydes and ketones depend on the lipophilicity and the reactivity of the analytes. Since the fluorescence enhancement of the sensing membrane at 296 nm/410 nm is only related to the formation of Schiff base, the measurement of aldehydes is independent of pH.
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Affiliation(s)
- Ronghua Yang
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
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Yang R, Li K, Wang K, Zhao F, Li N, Liu F. Porphyrin assembly on beta-cyclodextrin for selective sensing and detection of a zinc ion based on the dual emission fluorescence ratio. Anal Chem 2003; 75:612-21. [PMID: 12585492 DOI: 10.1021/ac020467n] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the present paper, a new cyclodextrin/porphyrin supramolecular sensitizer for zinc ion has been proposed based on the porphyrin dual fluorescence emission ratio. In aqueous solution, meso-tetraphenylporphyrin shows weak fluorescence, while in the presence of alkylated beta-cyclodextrin, it exhibits significant fluorescence enhancement by forming a cyclodextrin/porphyrin inclusion complex. Furthermore, the formation of a supramolecular complex causes a remarkable increase of the porphyrin metalation rate following the porphyrin fluorescence emission changes at two different emission wavelengths. The fluorescence emission of tetraphenylporphyrin at 656-nm bands decreases while that at 606 nm increases upon zinc ion interaction. Thus, the inclusion complex can behave as a ratiometric fluorescent sensor. Theoretically derivative equations for fluorescent ratiometry have been proposed for the first time. The feasibility of the proposed method is demonstrated by the performance of fluorometric detection of zinc ion. With the optimum conditions described, zinc ion in aqueous solution can be determined from 5.0 x 10(-7) to 2.5 x 10(-4) M. As the porphyrin electronic absorption and fluorescence emission are located in the visible range, and the fluorescence changes upon zinc ion interaction show high selectivity over biologically relevant cations, the inclusion complex could be used for biomedical application.
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Affiliation(s)
- Ronghua Yang
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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Vecer J, Holoubek A, Sigler K. Fluorescence behavior of the pH-sensitive probe carboxy SNARF-1 in suspension of liposomes. Photochem Photobiol 2001; 74:8-13. [PMID: 11460541 DOI: 10.1562/0031-8655(2001)074<0008:fbotps>2.0.co;2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
When exposed to the intracellular environment fluorescent probes sensitive to pH exhibit changes of photophysical characteristics as a result of an interaction of the dye molecule with cell constituents such as proteins, lipids or nucleic acids. This effect is reflected in calibration curves different from those found with the same dye in pure buffer solutions. To study an interaction of the probe 5'(and 6')-carboxy-10-dimethylamino-3-hydroxy- spiro[7H-benzo[c]xanthene-7,1'(3H)-isobenzofuran]-3'-one (carboxy SNARF-1) with membrane lipids, we measured its fluorescence in model systems of large unilamellar vesicles (LUV) prepared by extrusion. When the dye was removed from the bulk solution by gel filtration the relative fluorescence intensity of the lipid-bound dye form was enhanced, showing a strong interaction of the dye molecule with LUV membrane lipids. Surprisingly, the dye molecules seem to be bound predominantly to the outer surface of the lipid bilayer. The same situation was found with small unilamellar vesicles prepared by sonication. This effect makes it difficult to use carboxy SNARF-1 for measurements of the internal pH in suspensions of liposomes.
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Affiliation(s)
- J Vecer
- Institute of Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
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von Felten P, Bachofen R. Continuous monitoring of the cytoplasmic pH in Methanobacterium thermoautotrophicum using the intracellular factor F(420) as indicator. MICROBIOLOGY (READING, ENGLAND) 2000; 146 Pt 12:3245-3250. [PMID: 11101682 DOI: 10.1099/00221287-146-12-3245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The absorption spectrum of factor F(420) changes depending on the pH and the redox state of the cytoplasm. Specific wavelengths were used to calibrate absorption changes to allow the measurement of changes in the cytoplasmic pH in Methanobacterium thermoautotrophicum. Upon a hydrogen pulse, a rapid efflux of protons was observed. Under these energized conditions, the DeltapH amounts to 0.2-0.4 pH units at pH 6.6, and 0.6-0.8 pH units at pH 6.0. It decays within 10-20 s. In parallel, a sodium gradient is formed which has a slightly longer lifetime. Both DeltapH and DeltaPsi contribute to the proton-motive force present during methanogenesis. The energy-conversion rate, as indicated by the decay of the energized state of the cell, is fastest under growth conditions, i.e. at pH 6.9 and at a temperature of 58 degrees C.
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Affiliation(s)
- Peter von Felten
- Institute of Plant Biology, University of Zürich, Zollikerstraße 107, CH-8008 Zürich, Switzerland1
| | - Reinhard Bachofen
- Institute of Plant Biology, University of Zürich, Zollikerstraße 107, CH-8008 Zürich, Switzerland1
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Roos, Evers, Hieke, Tschope, Schumann. Shifts of intracellular pH distribution as a part of the signal mechanism leading to the elicitation of benzophenanthridine alkaloids . Phytoalexin biosynthesis in cultured cells of eschscholtzia californica. PLANT PHYSIOLOGY 1998; 118:349-64. [PMID: 9765521 PMCID: PMC34811 DOI: 10.1104/pp.118.2.349] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/1998] [Accepted: 06/30/1998] [Indexed: 05/21/2023]
Abstract
Cultured cells of Eschscholtzia californica (Californian poppy) respond to a yeast elicitor preparation or Penicillium cyclopium spores with the production of benzophenanthridine alkaloids, which are potent phytoalexins. Confocal pH mapping with the probe carboxy-seminaphthorhodafluor-1-acetoxymethylester revealed characteristic shifts of the pH distribution in challenged cells: within a few minutes after elicitor contact a transient acidification of cytoplasmic and nuclear areas occurred in parallel with an increase of the vacuolar pH. The change of proton concentration in the vacuole and in the extravacuolar area showed a nearly constant relation, indicating an efflux of vacuolar protons into the cytosol. A 10-min treatment with 2 mM butyric or pivalic acid caused a transient acidification of the cytoplasm comparable to that observed after elicitor contact and also induced alkaloid biosynthesis. Experimental depletion of the vacuolar proton pool reversibly prevented both the elicitor-triggered pH shifts and the induction of alkaloid biosynthesis. pH shifts and induction of alkaloid biosynthesis showed a similar dependence on the elicitor concentration. Net efflux of K+, alkalinization of the outer medium, and browning of the cells were evoked only at higher elicitor concentrations. We suggest that transient acidification of the cytoplasm via efflux of vacuolar protons is both a necessary and sufficient step in the signal path toward biosynthesis of benzophenanthridine alkaloids in Californian poppy cells.
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Affiliation(s)
- Roos
- Martin-Luther-University Halle-Wittenberg, College of Pharmacy, Pharmaceutical Biology, Department of Cellular Physiology/Biotechnology, Kurt-Mothes-Strasse 3, 06120 Halle (Saale), Germany
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