- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
An efficient new dual fluorescent pyrene based chemosensor for the detection of bismuth (III) and aluminium (III) ions and its applications in bio-imaging
摘要： A new simple pyrene based schiff base chemosensor 1 (nicotinic acid pyren-1-ylmethylene-hydrazide) has been constructed and is prepared from 1-pyrenecarboxaldehyde and nicotinic hydrazide. Notably, the chemosensor 1 exhibited remarkable colour changes while in the presence of trivalent metal ions like Bi3+ & Al3+ ion in DMSO-H2O, (1:1 v/v, HEPES = 50 mM, pH = 7.4). The UV-Vis spectral investigation of chemosensor 1 showed that the maximum absorption peak appeared at 378 nm. In emission studies, chemosensor 1 develops weak fluorescence, while upon the addition of Bi3+ and Al3+ ions, it exhibits an enhancement of fluorescence intensity. Nevertheless, rest of metal ions have no changes in the emission spectra. The association constant of chemosensor 1 for binding to Bi3+ & Al3+ system had a value of 1.27 × 104 M-1 and 1.53 × 104 M-1. The detection limits were 0.12 μM for Bi3+ and 0.17 μM for Al3+ respectively. The overall results reveal that chemosensor 1 can act as a dual-channel, highly selective, and sensitive probe for Bi3+ and Al3+ ions. Moreover, the fluorescence imaging of chemosensor 1 was applied in RAW 264.7 cell line and cytotoxicity assay prove that this chemosensor 1 is non-toxic as well as highly biocompatible.
关键词： Pyrene Schiff base,Spectroscopic studies,Live cell imaging,PET,Bi3+ and Al3+ detection
更新于2025-09-19 17:15:36
-
Hirshfeld surface, DFT vibrational (FT-IR) and electronic (UV–vis) studies on 4-amino-1H-1,2,4-triazolium nitrate
摘要： The title molecule, 4-amino-1H-1,2,4-triazolium nitrate ([4-am-1H-124-tr]+[NO3]–), was synthesized and characterized by means of Hirshfeld surface analysis, vibrational (FT-IR) and electronic (UV–vis) studies. A density functional theory (DFT) calculations were accomplished at B3LYP level using 6-311++G(2d,2p) basis set. A detailed analysis of the intermolecular interactions via Hirshfeld surface analysis and fingerprint plots revealed that the [4-am-1H-124-tr]+[NO3]– structure is stabilized mainly by formation of O···H/H···O and N···H/H···N hydrogen bonds. However, contributions from H?H and N···O/O···N contacts were also observed. UV–vis analysis (conducted in water-phase) clearly showed that charge transfers occurred in the title molecule. The energies of HOMO and LUMO, which were active in the electronic absorption spectrum, were obtained as well. Hence, a value of 5.2605 eV was obtained as a HOMO–LUMO energy gap. A comparative analysis between the calculated and experimental vibrational frequencies was carried out and significant bands were assigned. The results indicated a good correlation between experimental and theoretical IR frequencies.
关键词： 1,2,4-triazole,Hirshfeld surface,Spectroscopic studies,Density functional theory
更新于2025-09-09 09:28:46
-
Trap-Mediated Two-Step Sensitization of Manganese Dopants in Perovskite Nanocrystals
摘要： Halide perovskite nanocrystals hold promise for printable optoelectronic and photonic applications. Doping enhances their functionalities and is being investigated for substituting lead with environmentally friendlier elements. The most investigated dopant is Mn2+ that acts as a color center sensitized by the host excitons. The sensitization mechanism is far from understood and no comprehensive picture of the energy-transfer process has been proposed. Similarly, the role of shallow states - particularly abundant in defect tolerant materials - is still unknown. Here, we address this problem via spectroscopic studies at controlled excitation density and temperature on Mn:CsPbCl3 nanocrystals. Our results indicate a two-step process involving exciton localization in a shallow metastable state that mediates the thermally-assisted sensitization of the Mn2+-emission, which is completely quenched for T<200K. At T≤60K, however, such emission surprisingly reappears, suggesting direct energy-transfer from band-edge states. Electron spin resonance supports this picture revealing the signatures of conformational rearrangements below 70K, possibly removing the potential barrier for sensitization. Our results demystify anomalous behaviors of the exciton-to-Mn2+ energy-transfer mechanism and highlight the role of shallow defects in the photophysics of doped perovskite nanostructures.
关键词： Halide perovskite nanocrystals,energy-transfer,spectroscopic studies,Mn2+ dopants,shallow states
更新于2025-09-09 09:28:46