scholarly journals Optical Biomedical Diagnostics: Sensors with Optical Response Based on Two-Photon Excited Luminescent Dyes for Biomolecules Detection

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
V. M. Yashchuk ◽  
S. M. Yarmoluk ◽  
V. Yu. Kudrya ◽  
M. Yu. Losytskyy ◽  
V. P. Tokar ◽  
...  
Keyword(s):  
Cross Sections ◽  
Fluorescence Emission ◽  
Photon Absorption ◽  
Styryl Dyes ◽  
Dna Complexes ◽  
Two Photon ◽  
Photon Excitation ◽  
Dye Absorption ◽  
Dna Solutions ◽  
Biomolecules Detection

The spectral properties of novel styryl dyes developed for the biomacromolecules (such as DNA) detection and imaging were investigated. The energy structures of dye molecules were examined. The spectral data prove that dyes aggregate and interact with DNA. The essential increase of the fluorescence intensity of dyes in the presence of DNA was observed. The photostability and phototoxic influence on the DNA of several styryl dyes were studied by analyzing absorption, fluorescence, and phosphorescence spectra of these dyes and dye-DNA systems. Changes of the optical density value of dye-DNA solutions caused by the irradiation were fixed in the DNA and dye absorption wavelength regions. Fluorescence emission of dye-DNA complexes upon two-photon excitation at wavelength 1064 nm with the 20-nanosecond pulsed YAG:Nd3+ laser and at 840 nm with the 90 famtosecond pulsed Ti:sapphire laser was registered. The values of two-photon absorption cross-sections of dye-DNA complexes were evaluated.

scholarly journals Single cell in vivo brain optogenetic stimulation by two-photon excitation fluorescence transfer

2020 ◽  
Author(s):  
Lei Tong ◽  
Peng Yuan ◽  
Minggang Chen ◽  
Fuyi Chen ◽  
Joerg Bewersdorf ◽  
...  
Keyword(s):  
Single Cell ◽  
Cross Sections ◽  
Single Photon ◽  
Photon Absorption ◽  
Two Photon ◽  
Photon Excitation ◽  
All Optical ◽  
Stimulation Efficiency ◽  
And Control

AbstractOptogenetics at single-cell resolution can be achieved by two-photon stimulation; however, this requires intense or holographic illumination. We markedly improve stimulation efficiency by positioning fluorophores with high two-photon cross-sections adjacent to opsins. The two-photon-excited fluorescence matches the opsin absorbance and can stimulate opsins in a highly localized manner through efficient single-photon absorption. This indirect fluorescence transfer illumination allows experiments difficult to implement in the live brain such as all-optical neural interrogation and control of regional cerebral blood flow.

scholarly journals Multi-photon excitation in uncaging the small molecule bioregulator nitric oxide

2013 ◽  
Vol 371 (1995) ◽  
pp. 20120129 ◽  
Author(s):  
John V. Garcia ◽  
Fan Zhang ◽  
Peter C. Ford
Keyword(s):  
Nitric Oxide ◽  
Cross Sections ◽  
Near Infrared ◽  
Single Photon ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Nir Light ◽  
Photon Excitation ◽  
Ultraviolet Wavelength

Multi-photon excitation allows one to use tissue transmitting near-infrared (NIR) light to access excited states with energies corresponding to single-photon excitation in the visible or ultraviolet wavelength ranges. Here, we present an overview of the application of both simultaneous and sequential multi-photon excitation in studies directed towards the photochemical delivery (‘uncaging’) of bioactive small molecules such as nitric oxide (NO) to physiological targets. Particular focus will be directed towards the use of dyes with high two-photon absorption cross sections and lanthanide ion-doped upconverting nanoparticles as sensitizers to facilitate the uncaging of NO using NIR excitation.

Fluorescence of Styryl Dyes-DNA Complexes Induced by Single- and Two-Photon Excitation

2006 ◽  
Vol 16 (6) ◽  
pp. 783-791 ◽  
Author(s):  
V. P. Tokar ◽  
M. Yu. Losytskyy ◽  
V. B. Kovalska ◽  
D. V. Kryvorotenko ◽  
A. O. Balanda ◽  
...  
Keyword(s):  
Styryl Dyes ◽  
Dna Complexes ◽  
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.

Theoretical studies on the one- and two-photon absorption of tetrabenzoporphyrins and phthalocyanines

2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu
Keyword(s):  
Dipole Moment ◽  
Cross Sections ◽  
Density Functional ◽  
Transition Dipole Moment ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Order Of Magnitude ◽  
The One

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.

Determination of absolute two-photon excitation cross sections by in situ second-order autocorrelation

1995 ◽  
Vol 20 (23) ◽  
pp. 2372 ◽  
Author(s):  
Chris Xu ◽  
Winfried Denk ◽  
Jeffrey Guild ◽  
Watt W. Webb
Keyword(s):  
Cross Sections ◽  
Second Order ◽  
Two Photon ◽  
Photon Excitation ◽  
Excitation Cross Sections ◽  
Two Photon Excitation

Fluorescence anisotropy in indole under two-photon excitation in the spectral range 385–510 nm

2018 ◽  
Vol 20 (30) ◽  
pp. 19922-19931 ◽  
Author(s):  
M. E. Sasin ◽  
A. G. Smolin ◽  
K.-H. Gericke ◽  
E. Tokunaga ◽  
O. S. Vasyutinskii
Keyword(s):  
Propylene Glycol ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Fluorescence Anisotropy ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photon Excitation ◽  
Molecular Ground State

This paper presents the detailed study of two-photon excited fluorescence in indole dissolved in propylene glycol produced by two-photon absorption from the molecular ground state to several high lying excited states.

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