Conjugated Polymer-Based Hybrid Nanoparticles with Two-Photon Excitation and Near-Infrared Emission Features for Fluorescence Bioimaging within the Biological Window

2015 ◽  
Vol 7 (37) ◽  
pp. 20640-20648 ◽  
Author(s):  
Yanlin Lv ◽  
Peng Liu ◽  
Hui Ding ◽  
Yishi Wu ◽  
Yongli Yan ◽  
...  
2021 ◽  
Author(s):  
WEN-SHUO KUO ◽  
Chia-Yuan Chang ◽  
Ping-Ching Wu ◽  
Jiu-Yao Wang

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Wang ◽  
Huang Wu ◽  
Penghao Li ◽  
Su Chen ◽  
Leighton O. Jones ◽  
...  

Abstract Two-photon excited near-infrared fluorescence materials have garnered considerable attention because of their superior optical penetration, higher spatial resolution, and lower optical scattering compared with other optical materials. Herein, a convenient and efficient supramolecular approach is used to synthesize a two-photon excited near-infrared emissive co-crystalline material. A naphthalenediimide-based triangular macrocycle and coronene form selectively two co-crystals. The triangle-shaped co-crystal emits deep-red fluorescence, while the quadrangle-shaped co-crystal displays deep-red and near-infrared emission centered on 668 nm, which represents a 162 nm red-shift compared with its precursors. Benefiting from intermolecular charge transfer interactions, the two co-crystals possess higher calculated two-photon absorption cross-sections than those of their individual constituents. Their two-photon absorption bands reach into the NIR-II region of the electromagnetic spectrum. The quadrangle-shaped co-crystal constitutes a unique material that exhibits two-photon absorption and near-infrared emission simultaneously. This co-crystallization strategy holds considerable promise for the future design and synthesis of more advanced optical materials.


2017 ◽  
Author(s):  
Jackson T. Del Bonis-O’Donnell ◽  
Ralph H. Page ◽  
Abraham G. Beyene ◽  
Eric G. Tindall ◽  
Ian McFarlane ◽  
...  

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.


2019 ◽  
Vol 1081 ◽  
pp. 184-192 ◽  
Author(s):  
Guo-Jiang Mao ◽  
Guang-Qi Gao ◽  
Zhen-Zhen Liang ◽  
Ying-Ying Wang ◽  
Li Su ◽  
...  

2008 ◽  
Vol 19 (20) ◽  
pp. 205704 ◽  
Author(s):  
Qiang Lü ◽  
AiHua Li ◽  
FengYun Guo ◽  
Liang Sun ◽  
LianCheng Zhao

Small ◽  
2021 ◽  
pp. 2101185
Author(s):  
Fang‐Fang Shen ◽  
Yong Chen ◽  
Xiufang Xu ◽  
Hua‐Jiang Yu ◽  
Haoran Wang ◽  
...  

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