Showing papers by "Sophie Brasselet published in 1999"
TL;DR: This work reports new single-molecule experiments studying the effect of several parameters on the blinking process: pH, host matrix, and pumping intensity, and the primary measurement is the observed distribution of on-times and off-times.
Abstract: An interesting property of several yellow-emitting mutants of the green fluorescent protein (GFP) is that they switch between a fluorescent and a nonfluorescent state on a time scale of seconds. This peculiar blinking behavior was observed in single-molecule fluorescence studies of GFP mutants in poly(acrylamide) gels (Dickson, R. M.; et al. Nature 1997, 388, 355.). Utilizing primarily the yellow-emitting phenolate anion mutant EGFP, we report new single-molecule experiments studying the effect of several parameters on the blinking process: pH, host matrix, and pumping intensity. The primary measurement in these studies is the observed distribution of on-times and off-times. The on-time dynamics of EGFP are independent of pH over the range of 6−10, thus making protonation/deprotonation of the chromophore unlikely as the source of the blinking. The excitation intensity, however, has a considerable effect on the blinking: the on-times are shorter at high intensity. We compare these results to ensemble ble...
137 citations
TL;DR: Two new classes of octupolar nonlinear chromophores, deriving from 1,3,5-triazines and oligothienylic crystal violet analogues, have been synthesized and their nonlinear properties investigated using the harmonic light scattering experiment as discussed by the authors.
Abstract: Two new classes of octupolar nonlinear chromophores, deriving from 1,3,5-triazines and oligothienylic crystal violet analogues, have been synthesized and their nonlinear properties investigated using the harmonic light scattering experiment. The easy preparation of these molecules makes them attractive candidates for further applications. Off-resonant measurements show high nonlinearities together with an excellent transparency, which make these compounds of promising interest for the emerging schemes of nonlinear optical applications whereby the multipolar character of the chromophores is of particular importance.
108 citations
TL;DR: The ability of CH3 groups to form helical chains of C-Hπ interactions with phenyl rings leads to polar stacking of trigonal octupolar networks in a substituted triazine, and therefore to three-dimensional non-centrosymmetry.
51 citations
TL;DR: In this paper, the synthesis of 4,4′-bis(dialkylaminostyryl)-6,6′-dimethyl-2,2′-bipyridine ligands is described.
50 citations
TL;DR: This work compares and contrast the two methods in terms of the ability to follow the complex dynamics of this system, and concludes that the confocal method offers higher time resolution at the expense of parallelism.
Abstract: Single copies of four different phenolate ion mutants of the green fluorescent protein (GFP) exhibit a complex blinking and fluctuating behavior, a phenomenon that is hidden in measurements on large ensembles. Both total internal reflection microscopy and scanning confocal microscopy can be used to study the blinking dynamics, and autocorrelation analysis yields histograms of the correlation times for many individual molecules. While the total internal reflection method can follow several single molecules simultaneously, the confocal method offers higher time resolution at the expense of parallelism. We compare and contrast the two methods in terms of the ability to follow the complex dynamics of this system. Cytometry 36:232–238, 1999. © 1999 Wiley-Liss, Inc.
48 citations
TL;DR: In this article, photo-assisted electrical poling (PAP) and all-optical poling are performed by direct illumination of the guiding active layer through the gap between coplanar electrodes.
33 citations
TL;DR: In this article, a 3D all-organic octupoles of D 2d symmetry were designed and investigated by performing harmonic light scattering experiments in solution, and the resulting molecules exhibited larger nonlinearity and better transparency than p NA.
33 citations