Luminescence最新文献

Tetrachlorobisphenol A (TCBPA) is a kind of fire retardant extensively used in our life, but it can accumulate in organisms and potentially have toxic effects. Transferrin (TF) is a glycoprotein predominantly present in the blood plasma, serving as an essential mediator for the transportation of iron and other small molecules. In our study, various techniques including multi-spectroscopic and molecular docking were employed to examine the interaction between TCBPA and TF. The TF–TCBPA complex was formed with the binding constant (K_a) in 2.181 ± 0.035 × 10⁴ M⁻¹ at 298 K. ΔH and ΔS were all negative, which means dominant driving forces were van der Waals forces and H-bonds. The secondary structure of TF was changed by TCBPA, resulting in a decline in the α-helix structure, and a corresponding increase in the β-sheet structure. The molecular docking revealed that TCBPA was positioned within a pocket of TF, and it engaged in interactions with some amino acid residues through different forces. Importantly, the interaction between Tyr426/Asp392/His585 and TCBPA implies that TCBPA potentially interferes with the transportation of iron ions in vivo. All of above results indicated the adverse effects of TCBPA on the TF structure and activity should be more attention.

Aiming at net-zero emissions, most international and national policies focus on sustainable development goals. Hence, there is an immediate need for replacing carbon-intensive materials with biomaterials. In this respect, this article presents a road-map for moving from polymeric to sustainable waveguides in optical devices. Previous reports indicate that luminescent fibres exhibit better photon concentrations of nearly 30%–33% higher than flat-plate polymeric waveguides. It is also verified that the photon in-out ratio increases by 3.44 times when the waveguide geometry is changed from planar to an equivalent area of fibre bundle with the same luminophore. Meanwhile, transparent wood (Twood) is gaining attention as a green alternative to acrylic sheets. The structure and function of transparent wood conforms well with the fibre-based waveguides of luminescent solar concentrators (LSCs). Therefore, it is intriguing to compare Twood with intrinsic micro fibrillary interior with fibre-based LSC as a natural alternative. This review provides an in-depth analysis, emphasizing the benefits and associated challenges in using cylindrical concentrators over planar LSCs. The paper collects and compares the phenomenon of light guiding of cylindrical and fibre-based LSCs with that of Twood. It is important to consider the key points discussed here while making a transition towards sustainable waveguides.

The reaction-based probe perylene diimide–hydroxyphenyl benzothiazole (PR) can be used for the detection and discrimination of H₂S, DTT and Cys in 20% HEPES buffer–DMSO and DMSO. The H₂S induced radical anion formation of PR in 20% HEPES buffer and thiolysis of the ether bond of PR in DMSO. However, the addition of DTT showed only a decrease in the absorbance intensity and Cys showed insignificant behaviour towards PR in DMSO. The optical, AFM and DLS studies along with isolation of the reaction product in the model reaction support the interaction of the PR with bio thiols.

Anions play a crucial role in various environmental, chemical, and biological processes. Among various anions, the production of perchlorate (ClO₄⁻) ion is expected to rise in upcoming years, and thus, an efficient method for the detection of perchlorate ion is highly desirable. In this effort, a pyridyl-benzimidazole–based luminescent probe (RSB1) containing two N-H donor sites has been synthesized for selective detection of perchlorate ion. Different spectral techniques such as FT-IR, NMR, ESI-mass, UV–Vis, and fluorescence analyses have been used to characterize this probe. High selectivity of RSB1 for ClO₄⁻ was realized even in presence of strongly interfering species in aqueous-acetonitrile (CH₃CN-H₂O; 4:1, v/v) solution. Notably, RSB1 served as a “turn-on” perchlorate-responsive probe and exhibited an emission enhancement at 363 nm when excited at 300 nm. The detection limit (LoD) and the binding constant (K_b) values were depicted to be 0.121 μM and 2.6 × 10⁵ M⁻¹, respectively, while the binding mechanism for RSB1-ClO₄⁻ was validated via Job's plot, NMR, and DFT analyses. Furthermore, this probe was successfully employed to trace perchlorate in real samples such as tap water, distilled water, and soil samples with good to excellent recovery values.

Er³⁺-doped BaF₂ single crystals were investigated with two primary aims: first, to probe the infrared emissions from the ⁴I_11/2 level (around 1.0 μm) under 1500-nm excitation and, second, to use the crystal to enhance the efficiency of silicon-based solar cells through upconversion mechanism. Upon excitation at 1500 nm, the upconversion emission spectrum of the Er³⁺-doped BaF₂ single crystals, recorded in the range of 480–1080 nm, exhibited two well-structured visible bands at 538 and 650 nm, along with a strong near infrared emission at 971 nm. This strong 971-nm emission has an emission cross-section of approximately 0.23 × 10⁻²⁰ cm². As with any phenomenon inherent to energy transfer by upconversion, the ⁴I_11/2 fluorescence decay exhibits a rise time followed by a long decay of approximately 15 ms and a positive optical gain from the low values of the population inversion coefficient, which could potentially give rise to laser emission from this level. When we place our crystal on a photovoltaic device illuminated by 1500-nm wavelength radiation, we record a photocurrent of 300 μA at an illumination power of 85 mW. This indicates that the Er³⁺-doped BaF₂ crystal is highly suitable for significantly enhancing the efficiency of silicon-based solar cells.

Two novel nitrogen hybrid fluorescent sensors based on the ESIPT mechanism were successfully synthesized for the detection of fluoride ions (F⁻), and they exhibit high sensitivity and selectivity with a fast response. The detection limits even reach the parts per billion level. With the addition of F⁻, both sensors showed a ratiometric fluorescence change with a large Stokes shift. According to the hydrogen-1 (¹H) NMR titration, it was confirmed that the desilication reaction occurred between the sensors and F⁻. This work provides guidance for the subsequent development of F⁻ fluorescence sensors.

Based on nitrogen and phosphorus co-doped carbon dots (NP-CDs), a direct, quick, and selective sensing probe for fluorometric detection of rutin has been developed. Utilizing ethylene diamine tetra acetic acid (EDTA) as a carbon and nitrogen source and diammonium hydrogen phosphate (NH₄)₂HPO₄ as a nitrogen and phosphorus source. The NP-CDs were synthesized in less than 3 min with a straightforward one-step microwave pyrolysis process with a high quantum yield (63.8%). After being excited at λ = 360 nm, the produced NP-CDs displayed a maximum bluish fluorescence at λ_em of 420 nm. Rutin quenched the fluorescence of the produced NP-CDs based on the inner filter effect and static quenching processes. Along with the International Council of Harmonization (ICH) requirements, the developed spectrofluorometric method was validated. The linearity range was 0.50–35.00 μg/mL of rutin. The developed NP-CDs were successfully employed to determine rutin concentrations in marketed tablets. The developed method is quick, simple, consistent, sensitive, and selective, and it does not require expensive chemicals or specialized instruments. This study paves the path for future application of NP-CD in pharmaceutical analysis.