C–H⋯Au interactions and optical properties of [(P,P)4Au6]2+ molecular gold nanoclusters

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.

Download Full-text

Interrelation of transport and optical properties in gold nanoclusters

Applied Physics Letters ◽

10.1063/1.3491288 ◽

2010 ◽

Vol 97 (12) ◽

pp. 123108 ◽

Cited By ~ 3

Author(s):

G. W. Shu ◽

T. Y. Chen ◽

J. L. Shen ◽

C. A. J. Lin ◽

W. H. Chang ◽

...

Keyword(s):

Optical Properties ◽

Gold Nanoclusters

Download Full-text

Effect of Buffer on the Optical Properties of Irradiated Hydroxyethyl Methacrylate Copolymer

Journal of Materials Research ◽

10.1557/jmr.2002.0177 ◽

2002 ◽

Vol 17 (5) ◽

pp. 1199-1207

Author(s):

K. F. Chou ◽

C. C. Han ◽

Sanboh Lee

Keyword(s):

Optical Properties ◽

Irradiation Dose ◽

Ph Value ◽

Bathochromic Shift ◽

Cutoff Wavelength ◽

Hydroxyethyl Methacrylate ◽

Γ Irradiation ◽

Incident Wavelength ◽

Γ Ray ◽

Methacrylate Copolymer

The effect of buffer and γ irradiation on the optical properties of hydroxyethyl methacrylate (HEMA) copolymer was investigated. The transmission of HEMA copolymer decreased with the increase of irradiation dose and/or pH value of the buffer. The cutoff wavelength of HEMA copolymer exhibits a bathochromic shift as the γ-ray dose and/or pH value of buffer increases. The influence of atmosphere during γ-ray irradiation on the optical properties of HEMA copolymer was investigated. The change of optical properties of HEMA copolymer irradiated in air was more pronounced than that irradiated in vacuum. Light was scattered by holes in the polymer. The relationship between scattering intensity (Is) and incident wavelength (λ) can be described by the formula Is ∝ λ−n. The span of holes increases with the irradiation dose regardless of radiation atmosphere and pH value in the range of 4.1–6.5. A boundary between the inner and outer layers of HEMA copolymer irradiated in air was observed, separating two differential morphologies of holes.

Download Full-text

Optical Characterization of Sodium Fluorescein In Vitro and Ex Vivo

Frontiers in Oncology ◽

10.3389/fonc.2021.654300 ◽

2021 ◽

Vol 11 ◽

Author(s):

Ran Xu ◽

Wanda Teich ◽

Florian Frenzel ◽

Katrin Hoffmann ◽

Josefine Radke ◽

...

Keyword(s):

Optical Properties ◽

Laser Scanning ◽

Tumor Tissue ◽

Ex Vivo ◽

Bathochromic Shift ◽

Emission Spectra ◽

Optical Measurements ◽

Confocal Laser ◽

Sodium Fluorescein

ObjectiveThe utilization of fluorescein-guided biopsies and resection has been recently discussed as a suitable strategy to improve and expedite operative techniques for the resection of central nervous system (CNS) tumors. However, little is known about the optical properties of sodium fluorescein (NaFl) in human tumor tissue and their potential impact on ex vivo analyses involving fluorescence-based methods.MethodsTumor tissue was obtained from a study cohort of an observational study on the utilization of fluorescein-guided biopsy and resection (n=5). The optical properties of fluorescein-stained tissue were compared to the optical features of the dye in vitro and in control samples consisting of tumor tissue of high-grade glioma patients (n=3) without intravenous (i.v.) application of NaFl. The dye-exposed tumor tissues were used for optical measurements to confirm the detectability of NaFl emission ex vivo. The tissue samples were fixed in 4%PFA, immersed in 30% sucrose, embedded in Tissue-Tek OCT compound, and cut to 10 μm cryosections. Spatially resolved emission spectra from tumor samples were recorded on representative slides with a Confocal Laser Scanning Microscope FV1000 (Olympus GmbH, Hamburg, Germany) upon excitation with λexc = 488 nm.ResultsOptical measurements of fluorescein in 0.9% sodium chloride (NaCl) under in vitro conditions showed an absorption maximum of λmax abs = 479 nm as detected with spectrophotometer Specord 200 and an emission peak at λmax em = 538 nm recorded with the emCCD detection system of a custom-made microscope-based single particle setup using a 500 nm long-pass filter. Further measurements revealed pH- and concentration-dependent emission spectra of NaFl. Under ex vivo conditions, confocal laser scanning microscopy of fluorescein tumor samples revealed a slight bathochromic shift and a broadening of the emission band.ConclusionTumor uptake of NaFl leads to changes in the optical properties – a bathochromic shift and broadening of the emission band – possibly caused by the dye’s high pH sensitivity and concentration-dependent reabsorption acting as an inner filter of the dye’s emission, particularly in the short wavelength region of the emission spectrum where absorption and fluorescence overlap. Understanding the ex vivo optical properties of fluorescein is crucial for testing and validating its further applicability as an optical probe for intravital microscopy, immunofluorescence localization studies, and flow cytometry analysis.

Download Full-text

1,3,5-Triaryl-1,3,5-Triazinane-2,4,6-Trithiones: Synthesis, Electronic Structure and Linear Optical Properties

Molecules ◽

10.3390/molecules25225475 ◽

2020 ◽

Vol 25 (22) ◽

pp. 5475

Author(s):

Ismaël Rabouel ◽

Nicolas Richy ◽

Anissa Amar ◽

Abdou Boucekkine ◽

Thierry Roisnel ◽

...

Keyword(s):

Optical Properties ◽

Electronic Structure ◽

Dft Calculations ◽

Bathochromic Shift ◽

Spectroscopic Properties ◽

Absorption Bands ◽

Linear Optical Properties ◽

Linear Optical ◽

The Impact

The synthesis of four new 1,3,5-triaryl-1,3,5-triazinane-2,4,6-trithione derivatives (thioisocyanurates) and two new partially thionated analogues from the corresponding 1,3,5-triaryl-1,3,5-triazinane-2,4,6-triones (isocyanurates) is reported, together with their spectroscopic properties. DFT calculations and comparison with the corresponding isocyanurates evidence the impact of the oxygen-for-sulfur replacement on the electronic structure and linear optical properties of these heterocycles. A bathochromic shift of the absorption bands and more efficient quenching of the fluorescence was observed.

Download Full-text