Two-dimensional infrared (2D IR) spectroscopy was used to characterize the structure of a self-assembled polycyclic aromatic hydrocarbon (PAH), violanthrone-79. A local mode basis was constructed using spectroscopic and computational results of anthrone and monomer violanthrone-79. The vibrational modes in the spectral region 1550-1700 cm(-1), carbonyl stretching and in-plane ring breathing, are used as vibrational probes. The local mode basis and an electrostatic coupling model were applied to three nanoaggregate structures: parallel, antiparallel, and a chiral configuration produced by a 28° rotation from parallel. Angular disorder within each nanoaggregate configuration was also explored. This investigation is a first approach to probe self-assembled PAHs with 2D IR spectroscopy. The experimental and calculated 2D IR spectra align best when the violanthrone-79 molecules are in an anti-parallel configuration within the nanoaggregate.
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http://dx.doi.org/10.1063/1.4919637 | DOI Listing |
J Vis Exp
January 2025
Department of Biomedical Engineering, Washington University in St. Louis; Department of Obstetrics & Gynecology, Washington University in St. Louis;
For noninvasive light-based physiological monitoring, optimal wavelengths of individual tissue components can be identified using absorption spectroscopy. However, because of the lack of sensitivity of hardware at longer wavelengths, absorption spectroscopy has typically been applied for wavelengths in the visible (VIS) and near-infrared (NIR) range from 400 to 1,000 nm. Hardware advancements in the short-wave infrared (SWIR) range have enabled investigators to explore wavelengths in the ~1,000 nm to 3,000 nm range in which fall characteristic absorption peaks for lipid, protein, and water.
View Article and Find Full Text PDFMol Biol Rep
January 2025
Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Background: Breast carcinoma stands out as the most widespread invasive cancer and the top contributor to cancer-related mortality in women. Nanoparticles have emerged as promising tools in cancer detection, diagnosis, and prevention. In this study, the antitumor and apoptotic capability of silver nanoparticles synthesized through Scrophularia striata extract (AgNPs-SSE) was investigated toward breast cancer cells.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748 - Butantã, São Paulo, 05508-900, Brazil.
The conformational isomerization of nitrous acid (HONO) promoted by excitation of the or stretching normal coordinates is the first observed case of an infrared-induced photochemical reaction. The energy captured by the excited normal modes is redistributed into a highly excited vibrational level of the torsion normal coordinate, which is the isomerization reaction coordinate. Herein, we present simple numerical methods to qualitatively investigate the coupling between the normal coordinates and the possible gateways for vibrational energy redistribution leading to the isomerization process.
View Article and Find Full Text PDFRSC Adv
January 2025
Centre for Nano Bio Polymer Science and Technology, Department of Physics, St. Thomas College Palai Kerala 686574 India +919446126926.
We report a green approach to prepare carbon dots (CDs) with fresh tomatoes as carbon sources and amino acids as dopants (ACDs) by a microwave assisted method. The synthesised CDs were analysed by UV-visible absorption spectroscopy, photoluminescence spectroscopy, high resolution transmission electron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photo electron spectroscopy. An MTT assay was used to evaluate the cytotoxicity of CDs toward L929 cells and found that CDs exhibit low cytotoxicity.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, 147004, India.
Deep eutectic solvents (DESs) have attracted significant attention in recent years due to its environment friendly characteristics and its participation in the multi-heteroatom doping of carbon quantum dots (CQDs). In this work, we present a simple, fast, and environment-friendly microwave synthesis approach for the synthesis of DES-assisted nitrogen and chloride co-doped CQDs (N,Cl-CQDs) using a choline chloride-urea based DES. A biomass-based precursor, i.
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