Fiber optic fluorescent sensors

Wolfbeis O.S., Posch H.E., Fiber optic fluorescing sensor for ammonia, Anal. Chim. Acta 1986 185 321. 

Lieberman, S. H., Inman, S. M., Stromvall, E. J., Fiber Optic Fluorescence Sensors for Remote Detection of Chemical Species in Seawater , in Chemical Sensors, Tbrner, D. R. (ed.) London Electrochemical Society, 1987. 

Wolfbeis OS (1991) Fiber optic chemical sensors and biosensors, vol 1. CRC Press, Boca Raton, FL Wolfbeis OS (ed) (1992) Fiber optic chemical sensors and biosensors, vol 2. CRC Press, Boca Raton, FL Wolfbeis OS (2005) Materials for fluorescence-based optical chemical sensors. J Mater Chem 15 2657-2669 Wolfbeis OS, Posch HE (1986) Fiber-optic fluorescing sensor for ammonia. Anal Chim Acta 185 321-327 Wolfbeis OS, Weis LJ, Leiner MJP, Ziegler WE (1988) Fiber-optic fluorosensor for oxygen and carbon dioxide. Anal Chem 60 2028-2030... 

Fiber-Optic Fluorescence Sensors Fiber-optic probes have been used to demonstrate that several fluorescence determinations can be carried out at various locations well awav from a source and a... 

D. Walt, F. Milanovich, S. Klainer 1986 Polymer modification of a fluorescent fiber optic pH sensor... 

Shortreed M., Kopelman R., Kuhn M., Hoyland B., Fluorescent Fiber-Optic Calcium Sensor for Physiological Measurements, Anal. Chem. 1996 68 1414-1418. 

Munkholm C., Walt D.R., Milanovich F.P., Klainer S.M., Polymer modification of fiber optic chemical sensors as a method of enhancing fluorescence signal for pEl measurement, Analytical Chemistry 1986 58 1427-1430. 

Fuh M.R.S., Burgess L.W., Christian G.D., Single fiber-optic fluorescence enzyme-based sensor, Anal. Chem. 1988 60 433-435. 

Fluorescent pH indicators offer much better sensitivity than the classical dyes such as phenolphthalein, thymol blue, etc., based on color change. They are thus widely used in analytical chemistry, bioanalytical chemistry, cellular biology (for measuring intracellular pH), medicine (for monitoring pH and pCC>2 in blood pCC>2 is determined via the bicarbonate couple). Fluorescence microscopy can provide spatial information on pH. Moreover, remote sensing of pH is possible by means of fiber optic chemical sensors. 

R. B. Thompson and J. R. Lakowicz, Fiber optic pH sensor based on phase fluorescence lifetimes, Anal. Chem. 65, 853-856 (1993). 

K. T. V. Grattan, R. K. Selli, and A. W. Palmer, Ruby fluorescence wavelength division fiber-optic temperature sensor, Rev. Sei. Instrum. 57, 1231-1234 (1987). 

M. E. Lippitsch, J. Pusterhofer, M. J. P. Leiner and O. S. Wolifbeis, Fiber-optic oxygen sensor with the fluorescence decay time as the information carria, Anal. Chim. Acta. 205, 1-6 (1988). 

It is desirable to have means to measure organohalides such as carbon tetrachloride in situ in water and other environmental media. One approach to doing this has been demonstrated by the in situ analysis of chloroform-contaminated well water using remote fiber fluorimetry (RFF) and fiber optic chemical sensors (FOGS) (Milanovich 1986). With this approach, fluorescence of basic pyridine in the presence of an organohalide (Fujiwara reaction) is measured from a chemical sensor immersed in the water at the end of an optical fiber. Carbon tetrachloride undergoes a Fujiwara reaction, so its determination might be amenable to this approach. 

Keywords Absorption ARROW waveguide Biosensor Chemical sensor Confinement Dielectrics Evanescent field Fiber optics Fluorescence Hollow core Liquid-core Loss Optical mode Photonic crystal Refractive index Resolution Scattering Sensitivity Total internal reflection Waveguide... 

Combining the above described microfluidic differential resistive pulse sensor method with a miniature laser-fiber optic fluorescent detector, the simultaneous detection of fluorescent and non-fluorescent particles has been demonstrated [19], This method is simple, inexpensive, and easy to operate, and can achieve highly sensitive and accurate detection without relying on any conventional bulky instmments. Excellent agreement was achieved by comparing the results obtained by this chip system with the results from a commercial flow cytometer for a variety of samples of mixed fluorescent and non-fluore scent particles. 

A fiber-optic oxygen sensor with the fluorescence decay time (rather than its intensity) as the information carrier has been described by two groups [119, 120]. In the former work, a ruthenium complex is immobilized in silicone-rubber, and quenching by oxygen is measured by either lifetime or intensity measurements. The 337-nm line of a nitrogen laser served as the excitation line, and the dye was dissolved in a silicone-rubber membrane placed in the fluorimeter. This sensing membrane is reported to be highly specific, and chlorine and sulfur dioxide were the only interferents. 

Many fluorescence sensors are based, not on direct fluorescence, but on the quenching of fluorescence. Molecular oxygen, for example, is one of the best col-lisional quenchers. Oxygen can quench the fluorescence from polycyclic aromatic hydrocarbons complexes of ruthenium, osmium, iridium, and platinum and a number of surface-adsorbed heterocyclic molecules. An oxygen sensor can be made by immobilizing the fluorophore in a thin layer of silicone on the end of a fiber-optic bundle. Sensors for SO-, haliilcs, H-O-, and several other molecules have been ba.sed on fluorescence quenching. 

Fiber-optic chemical sensors for substances such as protons, asygea, and carbon di< dde have been developed. These sensors respond to specific substances in accordance with the fluorescent changes of fluorescent probes. An optical fiber-optic for pH can be couided to enzyme sensors when the enzymes cause a change in pH, which results in a change in fluorescent property of the probe compounds. These optical sensors are named Optrodes, and were extensively reviewed by Seitz (1). 

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