Abstract: We proposed and developed a series of fluorescent methods for analysis and investigation of biological systems with a view of future biotechnological and biomedical applications. The methods we describe have been built upon several photochemical and photophysics phenomena including fluorescence quenching, photochrome photoisomerization, and singlet-singlet and triplet-triplet energy transfer [1]. Three new types of molecular probes have been developed and employed for such studies: 1) dual fluorophore-nitroxide compounds [2-11]. fluorescent-photochrome molecules [12-18], super molecules containing both fluorescent and fluorescent quenching segments [19]. The fluorescence properties of the new probes were intensively exploited for several practical applications including a real time analysis of antioxidants, nitric oxide, superoxide, reactive radicals, trinitrotoluene and metal ions in picomolar concentration scale, investigation of molecular dynamics (fluidity) of biomembranes in a wide range characteristic times from seconds to nanoseconds, and characterization of surface systems. Owning high sensitivity, simplicity, availability of fluorescence techniques, these methods can be widely employed using standard fluorescent techniques and are potentially adaptable to fibrooptic sensoring and focal microscopy.

Brief Biography of the Speaker:
Gertz I. Likhtenshtein received his PhD (1963) and Doctor of Science (1972) degrees at the Semenov Institute of Chemical Physics, Russian academy of Science, Moscow. In 1976 this Institute granted him the Professor title. In 1965 he was appointed on the position of Head of Laboratory of Chemical Physics of Enzyme Catalysis. In 1992 Likhtenshtein moved to the Department of Chemistry, the Ben-Gurion University of Negev (Israel) on the full Professor position, was in charge of the Laboratory of Chemical Biophysics and has been emerited in 2003. Among his awards are the Medal of the Exhibition of Economic Achievement, the Diploma of Discovery USSR for works on nitrogen fixation , the USSR State Price for pioneering research on spin labeling in molecular biology, the V. V. Voevodsky International Price for Chemical Physics and the Diploma of the Israel Chemical Society. He is a member of the International ESR Society, the American Biophysical Society, the Israel Chemical Society and the Israel ESR Society. At present his main scientific interests focus on mechanism of the light energy conversion and on novel methods of immunoassay, NO and antioxidants analysis. Likhtenshtein authored 10 scientific books and about 380 papers.