scholarly journals Ligand shell size effects on one- and two-photon excitation fluorescence of zwitterion functionalized gold nanoclusters

2019 ◽  
Vol 21 (43) ◽  
pp. 23916-23921 ◽  
Author(s):  
Martina Perić ◽  
Željka Sanader Maršić ◽  
Isabelle Russier-Antoine ◽  
Hussein Fakhouri ◽  
Franck Bertorelle ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Effects ◽  
Gold Nanoclusters ◽  
Shell Size ◽  
Two Photon ◽  
Photon Excitation ◽  
Ligand Shell ◽  
Aqueous Solvent ◽  
The One ◽  
Two Photon Excitation

The effects of explicit ligands and of aqueous solvent on optical properties and in particular on the one- and two-photon excitation fluorescence of zwitterion functionalized gold nanoclusters have been studied.

Optical Properties of Photostimulable Near IR Centers in BaFCl Single Crystals Produced by Two-Photon Excitation

1998 ◽  
Vol 37 (Part 1, No. 4A) ◽  
pp. 1907-1910 ◽  
Author(s):  
Toshio Kurobori ◽  
Takashi Matsuki ◽  
Karnati Somaiah ◽  
Taku Kimura ◽  
Shoichi Nakamura ◽  
...  
Keyword(s):  
Optical Properties ◽  
Single Crystals ◽  
Two Photon ◽  
Near Ir ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-photon spectroscopy of the Schiff base of all-trans-retinal. Nature of the low-lying π π* singlet states

1985 ◽  
Vol 63 (7) ◽  
pp. 1967-1971 ◽  
Author(s):  
Lionel P. Murray ◽  
Robert R. Birge
Keyword(s):  
Excitation Spectrum ◽  
Polarized Light ◽  
Wavelength Region ◽  
Photon Absorption ◽  
Two Photon ◽  
Photon Excitation ◽  
The One ◽  
Photon Spectra ◽  
Π State ◽  
Two Photon Excitation

The two-photon excitation spectrum of all-trans-N-retinylidene-n-butylamine (ATRSB) in EPA at 77 K is obtained over the wavelength region from 370 to 455 nm (λex/2) using linearly polarized light. The two-photon excitation maximum is observed at ~422 nm (λex/2) and is red shifted ~2800 cm−1 from the one-photon absorption maximum at ~377 nm. We assign the two-photon excitation spectrum to the "1Ag*−" ← S0 transition which indicates that the "1Ag*−" π π* state lies below the "1Bu*+" π π* state in ATRSB. Comparisons of the one-photon absorption, two-photon excitation, and fluorescence spectra of ATRSB with the corresponding spectra of all-trans-retinal are presented. PPP-CISD calculations correctly predict the directions but not the magnitudes of the blue shifts of the π π* excited state transition energies in going from all-trans-retinal to ATRSB. We postulate that the "1Ag*−" π π* state is preferentially stabilized relative to both the ground state and the nearby "1Bu*+" state by hydrogen bonding to solvent molecules. Comparison of the spectra reported here with the two-photon spectra of rhodopsin provides further evidence that the chromophore in rhodopsin is protonated.

Two-photon excitation microscopy in cellular biophysics

1995 ◽  
Vol 53 ◽  
pp. 62-63
Author(s):  
David W. Piston ◽  
Brian D. Bennett ◽  
Robert G. Summers
Keyword(s):  
Confocal Microscopy ◽  
Laser Beam ◽  
Duty Cycle ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Two-photon excitation fluorescence microscopy in living systems

1993 ◽  
Vol 51 ◽  
pp. 154-155 ◽  
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Microscopy ◽  
Singlet State ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Two‐photon excitation fluorescence microscopy using a semiconductor laser

Bioimaging ◽  
1995 ◽  
Vol 3 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Pekka E Hänninen ◽  
Martin Schrader ◽  
Erkki Soini ◽  
Stefan W Hell
Keyword(s):  
Fluorescence Microscopy ◽  
Semiconductor Laser ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-Photon Excitation Imaging of Glucose Metabolism in Living Tissue

1997 ◽  
Vol 3 (S2) ◽  
pp. 305-306
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Collection Efficiency ◽  
Three Dimensional ◽  
Spatial Filter ◽  
Input Power ◽  
Photon Absorption ◽  
Focal Volume ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. It provides three-dimensional resolution and eliminates background equivalent to an ideal confocal microscope without requiring a confocal spatial filter, whose absence enhances fluorescence collection efficiency. This results in inherent submicron optical sectioning by excitation alone. In practice, TPEM is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 limits the average input power to less than 10 mW, only slightly greater than the power normally used in confocal microscopy. Because of the intensity-squared dependence of the two-photon absorption, the excitation is limited to the focal volume.

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