VIIIth International Symposium on Luminescence Spectrometry in Biomedical and Environmental Analysis. Detection Techniques and Applications in Chromatography and Capillary Electrophoresis
✍ Scribed by Prof. Dr. José Juan Santana Rodríguez
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 24 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0269-3879
No coin nor oath required. For personal study only.
✦ Synopsis
between 26 and 29 May 1998. This edition was organized by the University of Las Palmas de Gran Canaria (Spain) in collaboration with the Universities of Ghent (Belgium), Tokyo (Japan) and the Complutense of Madrid (Spain). One hundred and thirty eight delegates participated in the event. There were eight Invited Lectures and eight Invited Oral Contributions, and 131 posters were presented.
The meeting focused on the current status and future developments in the field of luminescence techniques (fluorescence, chemiluminescence, electrochemiluminescence, bioluminescence, phosphoresence and combinations with chromatography, capillary electrophoresis, flow-injection systems or immunoassays) used in drug quality control, clinical, chemical, biochemical, pharmaceutical, toxicological, food, and environmental analyses, and in related areas.
The lecture of the opening session was given by Prof. J. R. Lackowicz (University of Maryland, Baltimore, USA). Prof. Lackowicz gave an overview of the recent developments in Fluorescence Spectroscopy: Long Lifetime Metal-Ligand Probes, Multi-Photon Excitation and Clinical Chemistry. Nowadays, the instrumentation for time-resolved fluorescence is simple and inexpensive, making it possible to use lifetime measurements in fluorescence sensing. Lifetimebased sensing can be used for quantification of blood gases, blood electrolytes, and for cellular imaging.
The increasing availability of picosecond and femtosecond lasers has allowed two-photon excitation to be applied even in dilute solutions and for high sensitivity detection. Two-photon excitation has been used for detection of an anti-cancer drug, topotecan, in whole blood with excitation at 800 nm. Additionally, the localized excitation provided by two-photon excitation is being widely used in three-dimensional cellular imaging based on the confocal character of multi-photon excitation.
An important development in fluorescence spectroscopy has been the introduction of long lifetime metal-ligand probes. Numerous metal-ligand complexes are available with lifetimes ranging from 100 ns to 10 ms. Importantly, most of these complexes display polarized emission and are, thus, useful in measuring microsecond rotational diffusion of large macromolecules and for polarization immunoassays of substances of high molecular weight.
In the second Invited Lecture, Prof. J. Slavik (Czech Academy of Sciences, Prague, Czech Republic) talked on the topic Fluorescent Probes: Determination of Ion Concentration and Membrane Potential. Fluorescent probes for the measurement of ionic composition employ the old principle of litmus paper which gradually changes its colour from red to blue with increasing pH. It is assumed that ion-sensitive fluorescent probes exist in two forms, one free and one bound with the corresponding ion. Both forms can be spectroscopically distinguished from each other on the basis of changes in fluorescence excitation and/or fluorescence emission spectra and/or fluorescence lifetime. Dyes can be used for the measurement of the ionic composition of the medium as well as the cell interior. There are commercially available dyes for pH, calcium, magnesium, sodium, potassium, chloride, iron, zinc and some heavy metals.
The measurement of membrane potential is based either on the monitoring of the potential dependent distribution of the dye across the membrane according to the Nernst equation or on spectral changes of electrochromic dyes induced directly by the electrical field in the membrane.