scholarly journals Hot-Band-Absorption-Induced Anti-Stokes Fluorescence of Aggregation-Induced Emission Dots and the Influence on the Nonlinear Optical Effect

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 468
Author(s):  
Yuhuang Zhang ◽  
Jing Zhou ◽  
Shiyi Peng ◽  
Wenbin Yu ◽  
Xiaoxiao Fan ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Fluorescent Dyes ◽  
3D Structure ◽  
Deep Penetration ◽  
Nonlinear Optical Effect ◽  
Aggregation Induced Emission ◽  
Band Absorption ◽  
Hot Band ◽  
Anti Stokes

Hot-band absorption (HBA)-induced anti-Stokes fluorescence (ASF) with longer-wavelength excitation is one effective pathway to deep penetration and low autofluorescence in intravital fluorescence imaging, raising demands for fluorophores with broad spectra, high absorption, and strong emission. However, typical fluorescent dyes display some emission quenching when their concentration is increased in order to obtain brighter fluorescence. In this work, the HBA-induced ASF of aggregation-induced emission (AIE) dots is reported. BPN-BBTD dots were synthesized and confirmed with a fluorescence enhancement and a considerable ASF intensity. In addition, the mechanism of ASF and the HBA process of BPN-BBTD dots were carefully validated and discussed. To obtain the full advantages of the long-wavelength excitation and the short fluorescence lifetime in deep-tissue bioimaging, a large-depth ASF confocal microscopic imaging of in vivo cerebral vasculature was conducted under the excitation of a 980 nm continuous wave laser after intravenous injection of BPN-BBTD dots. Meanwhile, the 3D structure of the cerebrovascular network was successfully reconstructed.

scholarly journals Bright Near-infrared Anti-Stokes Fluorescence of ICG under Low Power CW Laser Excitation and its Applications in Bioimaging

2020 ◽  
Author(s):  
Jing Zhou ◽  
Di Wu ◽  
Zikang Ye ◽  
Dingwei Xue ◽  
Mubin He ◽  
...  
Keyword(s):  
Near Infrared ◽  
Biological Tissues ◽  
Delayed Fluorescence ◽  
Generation Mechanism ◽  
Photon Absorption ◽  
Infrared Band ◽  
Band Absorption ◽  
Hot Band ◽  
Anti Stokes

AbstractAnti-Stokes fluorescence was observed in ICG, a molecule approved by the FDA for clinical use. The wavelengths of its fluorescence are mainly located in the near-infrared band of 800 nm~900 nm, with a high quantum yield up to 8%. In order to know its generation mechanism, based on multi-photon absorption (MPA) theory, thermally activated delayed fluorescence (TADF) theory and hot band absorption theory, its power dependence, temperature dependence of absorption spectra and fluorescence spectra, and fluorescence lifetime were measured. Its generation mechanism was finally determined to be hot band absorption process. Since ICG showed bright anti-Stokes fluorescence in near-infrared region, which offers substantially longer penetration depth in biological tissues than visible light, excellent photostability and biosafety, we applied it to in vivo imaging and compared it with upconversion nanoparticles (UCNPs). The result is that ICG exhibited much stronger fluorescence than UCNPs, providing more anatomical information of samples. This contributes to a better choice for anti-Stokes fluorescence bioimaging.

scholarly journals Hot-band absorption of indocyanine green for advanced anti-stokes fluorescence bioimaging

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jing Zhou ◽  
Xiaoxiao Fan ◽  
Di Wu ◽  
Jie Liu ◽  
Yuhuang Zhang ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Indocyanine Green ◽  
Imaging Method ◽  
Urinary System ◽  
Excitation Light ◽  
Cw Laser ◽  
Band Absorption ◽  
Hot Band ◽  
Anti Stokes ◽  
Multi Mode

AbstractBright anti-Stokes fluorescence (ASF) in the first near-infrared spectral region (NIR-I, 800 nm–900 nm) under the excitation of a 915 nm continuous wave (CW) laser, is observed in Indocyanine Green (ICG), a dye approved by the Food and Drug Administration for clinical use. The dependence of fluorescence intensity on excitation light power and temperature, together with fluorescence lifetime measurement, establish this ASF to be originated from absorption from a thermally excited vibrational level (hot-band absorption), as shown in our experiments, which is stronger than the upconversion fluorescence from widely-used rare-earth ion doped nanoparticles. To test the utility of this ASF NIR-I probe for advanced bioimaging, we successively apply it for biothermal sensing, cerebral blood vessel tomography and blood stream velocimetry. Moreover, in combination with L1057 nanoparticles, which absorb the ASF of ICG and emit beyond 1100 nm, these two probes generate multi-mode images in two fluorescent channels under the excitation of a single 915 nm CW laser. One channel is used to monitor two overlapping organs, urinary system & blood vessel of a live mouse, while the other shows urinary system only. Using in intraoperative real-time monitoring, such multi-mode imaging method can be beneficial for visual guiding in anatomy of the urinary system to avoid any accidental injury to the surrounding blood vessels during surgery.

Single-Photon Hot Band Absorption Induced Anti-Stokes Luminescence of Rhodamine 101 in Mesostructured Thin Films

ChemPhysChem ◽  
2003 ◽  
Vol 4 (4) ◽  
pp. 392-395 ◽  
Author(s):  
Michael H. Bartl ◽  
Brian J. Scott ◽  
Gernot Wirnsberger ◽  
Alois Popitsch ◽  
Galen D. Stucky
Keyword(s):  
Thin Films ◽  
Single Photon ◽  
Band Absorption ◽  
Hot Band ◽  
Anti Stokes ◽  
Rhodamine 101

scholarly journals Flavanone-Based Fluorophores with Aggregation-Induced Emission Enhancement Characteristics for Mitochondria-Imaging and Zebrafish-Imaging

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3298
Author(s):  
Na Li ◽  
Liyan Liu ◽  
Huiqing Luo ◽  
Huaqiao Wang ◽  
Depo Yang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescent Dyes ◽  
Fluorescence Emission ◽  
In Vivo Studies ◽  
Aggregation Induced Emission ◽  
Emission Enhancement ◽  
High Fluorescence ◽  
Potential Use

Fluorophores with aggregation-induced emission enhancement (AIEE) characteristics applied in bioimaging have attracted more and more attention in recent years. In this work, a series of flavanone compounds with AIEE characteristics was developed and applied to fluorescence imaging of mitochondria and zebrafish. The compounds were readily prepared by the thermal dehydration of chalcone that was obtained by the reaction of o-hydroxyacetophenone and benzaldehyde. Two of these compounds showed significant AIEE characteristics by fluorescence performance experiments, including optical spectra, fluorescence spectra, fluorescence quantum yield (φF), fluorescence lifetime, and scanning electron microscopy (SEM). Compared with traditional organic fluorescent dyes, these compounds have high fluorescence emission and high fluorescence quantum yield in solid or aggregated state, which overcomes the shortcoming of aggregation-caused quenching (ACQ). More importantly, the two compounds exhibited low cytotoxicity and good cytocompatibility in A549 lung cells at the experimental concentration range and they specifically targeted mitochondria, which make it of great potential use in mitochondria labeling. In addition, they were embryonic membrane permeable and had different affinities for different tissues and organs of zebrafish, but mainly distributed in the digestive system, providing a basis for the application of such compounds in bioimaging. These AIEE compounds with superior properties could be of great potential use in mitochondria imaging and other in vivo studies.

Novel low-powered upconversion strategy to enhance anti-Stokes shift：Cascading the one-photon hot-band absorption and triplet sensitization based on Pd(II)octaethylporphyrin

2021 ◽  
Author(s):  
Xiaolei Ju ◽  
Lin Zhu ◽  
Lin Li ◽  
Changqing Ye ◽  
Zuoqin Liang ◽  
...  
Keyword(s):  
Energy Level ◽  
Vibrational Energy ◽  
Upconversion Emission ◽  
Photon Absorption ◽  
Vibrational Energy Level ◽  
Band Absorption ◽  
Hot Band ◽  
The One ◽  
Anti Stokes ◽  
Triplet Triplet Annihilation

Typical triplet sensitizer Pd(II)octaethylporphyrin (PdOEP) was firstly found to possess the absorption of hot vibrational energy-level and resulting the one-photon absorption (OPA) upconversion emission. Cascading hot-band OPA and triplet-triplet annihilation...

Optical imaging probes and their potential contribution to radiotracer development

2016 ◽  
Vol 55 (02) ◽  
pp. 51-62 ◽  
Author(s):  
S. Hermann ◽  
M. Schäfers ◽  
C. Höltke ◽  
A. Faust
Keyword(s):  
Optical Imaging ◽  
Fluorescent Dyes ◽  
Great Influence ◽  
Potential Contribution ◽  
Preclinical Evaluation ◽  
Guided Surgery ◽  
Fluorescence Guided Surgery ◽  
Imaging Probes ◽  
Unspecific Binding

SummaryOptical imaging has long been considered a method for histological or microscopic investigations. Over the last 15 years, however, this method was applied for preclinical molecular imaging and, just recently, was also able to show its principal potential for clinical applications (e.g. fluorescence-guided surgery). Reviewing the development and preclinical evaluation of new fluorescent dyes and target-specific dye conjugates, these often show characteristic patterns of their routes of excretion and biodistribution, which could also be interesting for the development and optimization of radiopharmaceuticals. Especially ionic charges show a great influence on biodistribution and netcharge and charge-distribution on a conjugate often determines unspecific binding or background signals in liver, kidney or intestine, and other organs.Learning from fluorescent probe behaviour in vivo and translating this knowledge to radio-pharmaceuticals might be useful to further optimize emerging and existing radiopharmaceuticals with respect to their biodistribution and thereby availability for binding to their targets.

Efficient artificial light-harvesting systems based on aggregation-induced emission constructed in supramolecular gels

Soft Matter ◽  
2021 ◽  
Author(s):  
Xinxian Ma ◽  
bo qiao ◽  
Jinlong Yue ◽  
JingJing Yu ◽  
yutao geng ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Rhodamine B ◽  
Fluorescent Dyes ◽  
Light Harvesting ◽  
Artificial Light ◽  
Efficient Energy Transfer ◽  
Aggregation Induced Emission ◽  
Efficient Energy ◽  
Harvesting Systems ◽  
Acyl Hydrazone

Based on a new designed acyl hydrazone gelator (G2), we developed an efficient energy transfer supramolecular organogel in glycol with two different hydrophobic fluorescent dyes rhodamine B (RhB) and acridine...

scholarly journals Fibrillar pharmacology of functionalized nanocellulose

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sam Wong ◽  
Simone Alidori ◽  
Barbara P. Mello ◽  
Bryan Aristega Almeida ◽  
David Ulmert ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Fluorescent Dyes ◽  
Pharmacokinetic Profile ◽  
Water Soluble ◽  
Size Exclusion ◽  
Hydroxyl Groups ◽  
Target Tissue ◽  
Exclusion Chromatography ◽  
Specific Accumulation

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.

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