Fluorescence kinetics

Pullerits T, Visscher K J, Hess S, Sundstrom V, Freiberg A, Timpmann K and Van Grondelle R 1994 Energy-transfer in the inhomogeneously broadened core antenna of purple bacteria-a simultaneous fit of low-intensity picosecond absorption and fluorescence kinetics Biophys. J. 66 236-48... 

It is impossible, therefore, to determine which mechanism is operative from the dimerization and fluorescence kinetic data. 

Principle Chlorophyll fluorescence is a sensitive and early indicator of damage to photosynthesis and to the physiology of the plant resulting from the effect of allelochemicals, which directly or indirectly affects the function of photosystem II (Bolhar-Nordenkemf et ah, 1989, Krause and Weiss 1991). This approach is convenient for a photosynthesis analysis in situ and in vivo and quick detection of otherwise invisible leaf damage. The photosynthetic plant efficiency was measured using the method of induced chlorophyll fluorescence kinetics of photosystem II [Fo, non-variable fluorescence Fm, maximum fluorescence Fv=Fm-Fo, variable fluorescence t /2, half the time required to reach maximum fluorescence from Fo to Fm and photosynthetic efficiency Fv/Fm]. 

Oquist, G. and Wass, R. (1988). A portable, microprocessor operated instrument for measuring chlorophyll fluorescence kinetics in stress physiology. Physiologia Plantarum 73 211-217. 

Fujita Y, Zenitani B, Nakao Y, Matsubara T (1972) Bacteriological studies on diseases of cultured laver. II. Bacteria associated with diseased laver. Bull Jap Soc Sci Fish 36 565-569 Gachon CMM, Kupper H, Kupper FC, Setlik I (2006) Single-cell chlorophyll fluorescence kinetic microscopy of Pylaiella littoralis (Phaeophyceae) infected by ChytricUum pofysiphoniae (Chytridiomycota). Eur J Phycol 41 395—403... 

W. R. Laws, J. B. A. Ross, H. R. Wyssbrod, J. M. Beechem, L. Brand, and J. C. Sutherland, Time-resolved fluorescence and H NMR studies of tyrosine and tyrosine analogues Correlation of NMR-determined rotamer populations and fluorescence kinetics, Biochemistry 25, 599-607 (1986). 

S. B. Phillips and R. L. Lyke, Fluorescence kinetics of systems with a quasi-continuum of excited states, Chem. Phys. Lett. 136, 247-251 (1987). 

If energy migration were ignored, the fluorescence kinetics of aryl vinyl polymers in solution could be expressed by the same set of rate constants as utilized for the meso- and d/-2,4-diarylpentanes. However, each chromophore in the polymer (ignoring chain ends) has two neighbors which may participate in excimer formation. A chromophore centered in a heterotactic triad, for example, would generate excimers on the syndiotactic side and on the isotactic side at the rates k M, and ki w r.r. 

The strong dependence of the Si/ICT lifetime on solvent polarity revealed first by transient absorption experiments in the visible region by Bautista et al. [8] was further confirmed by measurement of Si/ICT fluorescence using a streak-camera [11]. The Si/ICT state fluorescence kinetics of peridinin taken at 730 nm in solvents of different polarity are shown in Fig. 2b. The lifetime changes more than one order of magnitude, from 156 ps in n-hexane to 10.5 ps in methanol. In the middle-polarity solvents tetrahydrofuran and 2-propanol, the observed lifetimes are 77 and 54 ps, respectively. In all solvents, kinetic traces could be fitted by a single exponential decay independent of detection wavelength over nearly the entire fluorescence band (650 - 850 nm). The same decay times were also observed in transient absorption [11,12]. 

Many fluorescence kinetics fall into the ps time regime when non-radiative deactivation competes efficiently with the radiative transition. The natural... 

Figure 8.12 Laser-induced fluorescence kinetics of dissociation reactions. I, reaction of Nal followed at the absorption wavelength of the excited molecule II, same reaction monitored at the absorption wavelength of the free Na atom III, reaction of NaBr, followed at the absorption wavelength of the excited molecule...

Fig. 3.20. Signals of fluorescence kinetics representing fly-through relaxation of an optically depopulated initial level (a) rectangular profile of the beam (b) limited Gaussian profile (c) unlimited Gaussian profile (d) experimentally registered signal. Values of the non-linearity parameter Bwpvp/ro are shown in brackets.

Knowledge of the Maillard reaction is being extended very actively in many different ways. The participation of free radicals has already been dealt with in Chapter 2 and work on colour and flavour aspects is being deferred to Chapters 4 and 5, respectively. This chapter deals with a number of relatively disparate topics, namely, the effects of pH, high pressure, 7g, and the use as reactants of amines other than amino acids, of lipids, and of oligo- and polysaccharides, as well as the determination of a-dicarbonyl intermediates, control of aldol/retroaldol reactions, fluorescence, kinetic aspects, and sites of protein glycation. 

Figure 4. Fluorescence kinetics of erythrosin in water measured by the streak camera-OMA system. The decay is a single exponential with a decay time of 78...

Figure 6. Fluorescence kinetics from spinach measured with streak camera-...

Fig. 18. Schematic of apparatus used to measure fluorescence kinetics with a streak camera. The Nd glass laser emits a train of one hundred 1.06 pm pulses separated by 6 ns. A single pulse in the earlier portion of the train is selected by a Pockels cell and crossed polarizers (Pi and P2). The high voltage pulse ( 5 ns) at the Pockels cell is supplied by a laser triggered spark gap and a charged line. The single pulse ( 8 ps, 109 W) can be amplified. The second harmonic is generated from a phase matched KDP crystal. Beam splitters provide two side beams beam (1) triggers the streak camera beam (2) arriving at the streak camera at an earlier time acts as a calibrating pulse. The main 0.53 pm beam excites the sample for fluorescence measurement. The fluorescence collected with f/1.25 optics is focused into the 30 pm slit of the streak camera. The streak produced at the phosphorescent screen is recorded by an optical multichannel analyzer. (After ref. 67.)...

Fig. 19. (a) Fluorescence kinetics of erythrosin in water measured by a streak camera, (b) Single exponential nature of the fluorescence decay of erythrosin in solution. o> Full trace of the decay curve in (a) solid line has a decay time of 78 ps. The curve is arbitrarily shifted from the zero of the abscissa. (After ref. 67.)... 

The fluorescence kinetics of erythrosin in water measured with the system described above is shown in Fig. 19. The fluorescence decay showed single exponential behavior with a lifetime of 78 ps. In acetone, the fluorescence lifetime was 2.4 ns. The lifetime varied linearly between 2.4 ns and 75 5 ps with the mole fraction of water in the acetone—water mixture. The quenching of fluorescence from erythrosin in acetone—water mixtures was interpreted in terms of the kinetics of solvent quenching and was attributed to a change in the intersystem crossing rate. 

Fig. 9. Avidity controlled interaction kinetics between the anti-biotin antibody 2F5 and the surface-confined biotin moieties. (A) Normalized SPR curves of the 2F5 association/dissociation process on surfaces with relatively high biotin densities. (B) Fluorescence kinetic curves of the 2F5 association/dissociation on surfaces with lower biotin densities.

Fig. 10. Sensitivity evaluation of SPFS on planar surfaces. (1), (2), (3) are fluorescence kinetic curves of the binding of L2F5 to surfaces of different biotin densities of % — 0.0004, 0.0001, 0, respectively. (4), (5), (6) are fluorescence kinetic curves of the binding of AF-RaM to 2F5 (mouse IgG) bound surfaces of different X = 0.0004, 0.0001, 0, respectively.

In addition to the above plate readers, several other types are used to perform specific tasks in screening laboratories. Fluorescence kinetic plate readers can measure an assay plate quickly and... 

M,ller, M. G., Griebenow, K., and Holzwarth, A. R., 1991, Primary processes in isolated bacterial reaction centers from Rhodobacter sphaeroides studied by picosecond fluorescence kinetics. Chem. Phys. Letts., 199 4659469. 

Acknowledgment. Many of the results outlined above have become possible due to support by BMFT (fluorescence kinetics using BESSY synchrotron radiation, projects 05314 FAI5, 05414 FABl and 05 5KT FAB) and DFG (Heisenberg fellowship to the author), and due to the skill of my coworkers. I also want to thank my collaborators from other laboratories abroad and in Germany, who provided the stimulus for many discussions and helped to develop the ideas presented here. I am especially grateful to Professor Z.R. Grabowski for his open-minded collaboration with the new aspects of TICT formation outlined here. 

Kiipper, H., Ferimazova, N., Sedik, 1., and Berman-Frank, 1. (2004). Traffic lights in Trichodesmium. Regulation of photosynthesis for nitrogen fixation studied by chlorophyU fluorescence kinetic microscopy. Plant Physiol. 135, 2120—2133. ... 

TA Roeiofs, M Giibert, VA Shuvaiov and AR Hoizwarth (1991) Picosecond fluorescence kinetics of the D -D2-cyt-b-559 photosystem II reaction center complex. Energy transfer and primary charge separation processes. Biochim Biophys Acta 1060 237-244... 

I. Gomez, F.L. Figueroa (1998). Effects of solar UV stress on chlorophyll fluorescence kinetics of intertidal macroalgae from southern Spain a case study in Gelidium species. J. Appl Phycol, 10, 285-294. 

Fluorescence Kinetic-Based Measurements. Our studies of the reaction rate determination of thiamine (vitamin Bl) will be used to demonstrate the unique capabilities of rapid acquisition of spectra in kinetic measurements. The kinetic method is based on the oxidation of thiamine by Hg + in basic solutions to highly fluorescent thiochrome (16) The initial rate, taken as the change in fluorescence signal at 444 nm that occurs in a fixed time after mixing the sample and reagents, is directly proportional to the thiamine concentration. 

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