Solid state red biphotonic excited emission from small dipolar fluorophores

2016 ◽  
Vol 4 (4) ◽  
pp. 766-779 ◽  
Author(s):  
Martin Ipuy ◽  
Yuan-Yuan Liao ◽  
Erwann Jeanneau ◽  
Patrice L. Baldeck ◽  
Yann Bretonnière ◽  
...  
Keyword(s):  
Solid State ◽  
Penetration Depth ◽  
Near Infrared ◽  
Emission Wavelength ◽  
Infrared Range ◽  
Two Photon ◽  
Photon Excitation ◽  
Near Infrared Range ◽  
Two Photon Excitation

Dyes emitting in the solid state in the red or near-infrared range are much sought after for application in bioimaging especially if the long emission wavelength can be combined with two-photon excitation to provide unique contrast and penetration depth.

scholarly journals Two-Photon–NIR-II Antimicrobial Graphene-Nanoagent for Ultraviolet–NIR Imaging and Photoinactivation

2021 ◽  
Author(s):  
WEN-SHUO KUO ◽  
Chia-Yuan Chang ◽  
Ping-Ching Wu ◽  
Jiu-Yao Wang
Keyword(s):  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Chemical Modification ◽  
Near Infrared ◽  
Photon Absorption ◽  
Excitation Wavelength ◽  
Strong Electron ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Abstract BackgroundNitrogen doping and amino-group functionalization, which result in strong electron donation, can be achieved through chemical modification. Large π-conjugated systems of graphene quantum dot (GQD)-based materials acting as electron donors can be chemically manipulated with low two-photon excitation energy in a short photoexcitation time for improving the charge transfer efficiency of sorted nitrogen-doped amino acid–functionalized GQDs (sorted amino-N-GQDs). ResultsIn this study, a self-developed femtosecond Ti-sapphire laser optical system (222.7 nJ pixel−1 with 100-170 scans, approximately 0.65-1.11 s of total effective exposure times; excitation wavelength: 960 nm in the near-infrared II region) was used for chemical modification. The sorted amino-N-GQDs exhibited enhanced two-photon absorption, post-two-photon excitation stability, two-photon excitation cross-section, and two-photon luminescence through the radiative pathway. The lifetime and quantum yield of the sorted amino-N-GQDs decreased and increased, respectively. Furthermore, the sorted amino-N-GQDs exhibited excitation-wavelength-independent photoluminescence in the near-infrared region and generated reactive oxygen species after two-photon excitation. An increase in the size of the sorted amino-N-GQDs boosted photochemical and electrochemical efficacy and resulted in high photoluminescence quantum yield and highly efficient two-photon photodynamic therapy. ConclusionThe sorted dots can be used in two-photon contrast probes for tracking and localizing analytes during two-photon imaging in a biological environment and for conducting two-photon photodynamic therapy for eliminating infectious microbes.

scholarly journals Dual Near Infrared Two-Photon Microscopy for Deep-Tissue Dopamine Nanosensor Imaging

2017 ◽  
Author(s):  
Jackson T. Del Bonis-O’Donnell ◽  
Ralph H. Page ◽  
Abraham G. Beyene ◽  
Eric G. Tindall ◽  
Ian McFarlane ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photon Absorption ◽  
Deep Tissue ◽  
Biologically Relevant ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Tissue Phantom ◽  
Photon Excitation ◽  
Photon Absorption And Scattering ◽  
Two Photon Excitation

A key limitation for achieving deep imaging in biological structures lies in photon absorption and scattering leading to attenuation of fluorescence. In particular, neurotransmitter imaging is challenging in the biologically-relevant context of the intact brain, for which photons must traverse the cranium, skin and bone. Thus, fluorescence imaging is limited to the surface cortical layers of the brain, only achievable with craniotomy. Herein, we describe optimal excitation and emission wavelengths for through-cranium imaging, and demonstrate that near-infrared emissive nanosensors can be photoexcited using a two-photon 1560 nm excitation source. Dopamine-sensitive nanosensors can undergo two-photon excitation, and provide chirality-dependent responses selective for dopamine with fluorescent turn-on responses varying between 20% and 350%. We further calculate the two-photon absorption cross-section and quantum yield of dopamine nanosensors, and confirm a two-photon power law relationship for the nanosensor excitation process. Finally, we show improved image quality of the nanosensors embedded 2 mm deep into a brain-mimetic tissue phantom, whereby one-photon excitation yields 42% scattering, in contrast to 4% scattering when the same object is imaged under two-photon excitation. Our approach overcomes traditional limitations in deep-tissue fluorescence microscopy, and can enable neurotransmitter imaging in the biologically-relevant milieu of the intact and living brain.

The two-photon excitation of SiO2-coated Y2O3:Eu3+ nanoparticles by a near-infrared femtosecond laser

2008 ◽  
Vol 19 (20) ◽  
pp. 205704 ◽  
Author(s):  
Qiang Lü ◽  
AiHua Li ◽  
FengYun Guo ◽  
Liang Sun ◽  
LianCheng Zhao
Keyword(s):  
Femtosecond Laser ◽  
Near Infrared ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

A Three‐Color Fluorescent Supramolecular Nanoassembly of Phototherapeutics Activable by Two‐Photon Excitation with Near‐Infrared Light

2019 ◽  
Vol 25 (29) ◽  
pp. 7091-7095 ◽  
Author(s):  
Aurore Fraix ◽  
Vladimir Kirejev ◽  
Milo Malanga ◽  
Éva Fenyvesi ◽  
Szabolcs Béni ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation
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