JBCS

Cationic tricyclic photosensitisers such as the phenothiazinium S137 (shown) are highly effective bacterial killers when activated by the correct wavelength light. Microbial killing by reactive oxygen species such as singlet oxygen (¹O₂) is unaffected by conventional antimicrobial resistance.

Raman processes (left) and photoluminescence with energy transfer (right) - both are phonon-assisted optical transitions; the energy levels 1 and 2 are supposed to be thermally coupled. The intensity ratios I_S/I_AS and I₂/I₁ allow temperature measurements.

This review presents results on the nonlinear optical characterization of special glasses, as well as on the achievements obtained on the use of femtosecond laser micromachining for advanced processing of such glasses.

Photochemistry without light: generation of typical photoproducts by chemiexcitation.

Photodynamic therapy (PDT) is based on the combination of nontoxic components (photosensitizer, PS + oxygen) that when activated by low energy light generates cytotoxic species, such as reactive oxygen species (ROS), capable of causing direct damage to biomolecules, triggering tumor cells death. In recent years, the combination of PSs and drug delivery systems is been more extensively explored in order to increase the selectivity and photodynamic efficiency, thus reducing further the side effects of that therapy.

This review presents an introduction regarding the spectroscopic properties of rare earth elements and their application in solid state optical devices, with a brief discussion of the main mechanisms of light absorption and emission by 4f elements.

We present novel ESIPT fluorescent triazinyl-benzazole derivatives. The compounds are photoactive in the blue-orange region with a large Stokes' shift.

4-(Pyren-1-ylimino)methylphenol and its silylated derivative were synthesized and employed in F^- and CN^- colorimetric detection in solution. These compounds were used in two strategies, as a chemosensor based on acid-base or in a chemodosimeter approach.

Enhancement of the photoluminescence intensity at ca. 1300 nm attributed to the local field growth in the vicinity of the silver nanoparticles in Bi₂O₃-GeO₂ glasses. This result and the others presented in this work illustrate the large potential of Bi₂O₃-GeO₂ with silver nanoparticles (Ag-NPs) to be used in photonic devices.

Emission at 1000 nm generated by UV-Vis to near infrared (NIR) energy conversion from nanocomposite and planar waveguide.

New luminescent asparagine (Asn) modified organic-inorganic hybrid composites based on Tb³⁺-Al³⁺ host were obtained. Asn was observed to enhance the host-to-dopant energy transfer.

The 1 mol% Er³⁺ doped 80SiO₂:20GeO₂ have an infrared emission, due to the Er^{3+ 4}I_13/2 → ⁴I_13/2 transition, 4.9 times higher than the for 90SiO₂:10GeO₂.

Phosphors arranged in a form of sheets with 60 nm of thickness are excited by the light emission region of a light emitting diode emitting ultraviolet (UV, 275, 394 nm), blue (465 nm) or green (525 nm) light displaying strong and narrow red emission lines at around 614 nm.

Infrared spectra of bone, dentine, and enamel, in which organic and inorganic matrix can be affected by high intensity laser irradiation used in dentistry or by gamma radiation in medicine.

Light-based technology can potentiate the dissemination of phototherapy studies to determine its suitable application in health sciences.

Chitosan doped with Eu(CF₃SO₃)₃ presents emissions from blue to red that can be tuned to yield white light. Addition of Li^I can lead to electroluminescent devices.

The photochromic response of Ormosil-phosphotungstate hybrid films can be enhanced up to 7 times by doping with alkaline earth metal cation and tailored by varying the matrix composition.

Red emission spectra of the glasses with different amounts of MnO (left) and samples 0Mn and 10Mn without irradiation (right, upper) and during irradiation with λ = 408 nm (right, bottom).

New non-symmetric and positively-charged PDT photosensitizers were obtained by using inexpensive copper-chlorophyllin as raw material and a simple chemical route.

Carbon dots (C-dots) have been synthesized from brewing industry waste and applied as bioprobes for live cell-imaging experiments with interesting results.

Commission Internationale de l'Eclairage (CIE) diagram and photographs [RE(TLA):Eu³⁺] and RE₂O₃:Eu³⁺, excited under UV radiation.