The present work reports the synthesis of indigo-dye-incorporated polyaniline (Indigo-PANI), poly(1-naphthylamine) (Indigo-PNA), poly(o-phenylenediamine) (Indigo-POPD), polypyrrole (Indigo-PPy), and polythiophene (Indigo-PTh) via an ultrasound-assisted method. The synthesized oligomers were characterized using FTIR, UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence studies, and thermogravimetric analysis (TGA). The experimental data were theoretically compared to analyze the vibrational and electronic spectra via time-dependent density-functional theory (TD-DFT) by applying the Becke, three-parameter, and Lee-Yang-Parr (B3LYP) method with a 6-311G (d,p) basis set. The experimental, theoretical vibrational, and electronic spectra were found to be in close agreement and confirmed the successful incorporation of indigo dye in PANI, PNA, POPD, PPy, and PTh. These studies confirmed that multifunctional oligomers could be synthesized through a facile technique by incorporating dye moieties to enhance their optoelectronic properties, allowing them to be utilized as near-infrared-emitting probes for photodynamic therapy.

In this study, silver sulfide nanoparticles (Ag2SNP\'s) were successfully produced by using fruit extracts of Phyllanthus emblica. UV-vis, FTIR, XRD with SEM and EDX techniques were used for the synthesis process and for characterization of the resulting nanostructures. According to the findings, the fabricated nanostructure had a monoclinic crystal structure, measuring 44 nm in grain size, and its strain was 1.82 × 10-3. As revealed by SEM analysis, the synthesized nanostructure consists of irregular spherical and triangular shapes. The presence of silver (Ag) and sulfur (S) was also confirmed through EDX spectra. Furthermore, Ag2S nanoparticles were tested for their ability to effectively inhibit gram-positive and gram-negative bacterial growth. As a result of this study, it was clearly demonstrated that Ag2S nanoparticles possess powerful antibacterial properties, particularly when it came to inhibiting Escherichia coli growth. Ag2S nanoparticles had high total H2O2 and flavonoid concentrations and the greatest overall antioxidant activity, according to the evaluation of antioxidant activity of the samples. The results obtained from the P. emblica fruit extract were followed by those obtained from Ag2S nanoparticles were reported in detail. RESEARCH HIGHLIGHTS: Innovative Ag2SNP synthesis using Phyllanthus emblica fruit extract. SEM with EDX revealed a monoclinic crystal structure with a grain size of 44 nm and a strain of 1.82 × 10-3. Many of these applications are demonstrated by the potential of Ag2SNPs to treat and combat bacteria, particularly Escherichia coli. A peak at 653 cm-1 indicates the presence of primary sulfide aliphatic C-S extension vibrations. The abundant H2O2 and NO2 found in P. emblica nanocomposites make them potent antioxidants.

Aspirin is a commonly used nonsteroidal anti-inflammatory drug, associated with many adverse effects. The adverse effects of aspirin such as tinnitus, Reye\'s syndrome and gastrointestinal bleeding are caused due to conversion of aspirin into its active metabolite salicylic acid after oral intake. Glutathione is a naturally occurring antioxidant produced by the liver and nerve cells in the central nervous system. It helps to metabolize toxins, break down free radicles, and support immune function. This study aims to investigate and explore the possibility of inhibiting aspirin to salicylic acid conversion in presence of glutathione at a molecular level using spectroscopic techniques such as UV-Visible absorption, time-Resolved and time-dependent fluorescence and theoretical DFT/ TD-DFT calculations. The results of steady state fluorescence spectroscopy and time-dependent fluorescence indicated that the aspirin to salicylic acid conversion is considerably inhibited in presence of glutathione. Further, the results presented here might have significant clinical implications for individuals with variations in glutathione level.

Environmental sustainability, resource availability, and cost-effectiveness are the driving forces behind the search for natural sensitised dyes to replace synthetic ones. Using a combination of pigments as the sensitised dye in dye-sensitised solar cells (DSSCs) offers several advantages over using a single pigment. In this present study, natural dyes with different pigments were extracted from three local plants: Coccinia grandis (Ivy gourd leaves, IGL), Oryza sativa Linn (Black glutinous rice, BGR), and Curcuma longa L. (Turmeric, TM). Each colour extract absorbed various wavelengths of light. It was found that the single IGL-dye (green) had a greater light absorption and energy band gap over visible light than other extracts (dyes). Then combinations of these dyes were examined. A sensitised dye combination with a primary to secondary dye in a volumetric ratio of 80/20 exhibited multiple energy band gaps, implying multiple electron excitations at different photon energy levels. Compared to other mixed dyes, IGL/TM-dye had the highest absorbance and electron excitation at three wavelengths with the smallest energy band gap values of 1.74, 2.51, and 2.59 eV. The IGL-dye had the highest DSSC efficiency of 0.15 % for single dyes, followed by the TM-dye and BGR-dye, which had 0.12 % and 0.04 %, respectively. Interestingly, for combined dyes, the IGL/TM dye increased DSSC efficiency to 0.3 %. Since natural dyes tend to be less effective in DSSCs than synthetic dyes because they have a narrower absorption range, higher redox potentials, shorter operational lifetimes, higher rates of electron recombination, and different molecular structures, the dye co-sensitization strategy is one of the best ways to make more effective cells in the future.

Here, in this article, we present the design and synthesis of 1,2,3-triazole allied Schiff base functionalized organosilanes 6(a-e) utilising single step approach. These compounds were further characterised using NMR (1H, 13C) and mass spectrometry. Furthermore, UV-Visible and fluorescence spectroscopy showed that compound 6a had a high selectivityto Sn(II) and Al(III) metal ions compared to other relevant metal ions with lowlimit of detection (LOD) values. Suppression of -C=N isomerization, constrained intramolecular charge transfer (ICT), and complexation with Sn(II)/Al(III) ions (Chelation Enhanced Fluorescence (CHEF)) results in probe 6a\'s enhanced turn on fluorescence toward the detection of Sn(II) and Al(III) ions. Probe 6a was a strong candidate for the detection of Sn(II) and Al(III) ions due to its selectivity, reversibility, and competitiveness. Since the detecting phenomenon can be reversed, the sensor 6a perfectly mimics the INHIBIT molecular logic gate. Also, computational study utilising DFT technique was used to shed light on the complexation mode of 6a with Sn(II) and Al(III) metal ions. The compound 6a\'s antibacterial activity has also been successfully tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Additionally, the compound 6a was docked to the E. coli and S. aureus proteins, which exhibited excellent results with binding energies of -7.18 Kcal mol-1 and -7.05 Kcal mol-1, respectively. As both in-vitro and docking studies demonstrated anti-bacterial activity of the probe 6a, it may be anticipated that the probe has potential to serve as anti-bacterial drug in nearly future.

In the current study, the co-precipitation technique was employed for the synthesis of Cadmium oxide (CdO) and Copper‒doped Cadmium oxide (Cu‒CdO) nanoparticles. The synthesized samples were subjected to powder X-Ray diffraction (P-XRD), Field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray (EDX), Fourier transforms Infrared (FT-IR), UV-Vis spectroscopy, photoluminescence (PL), laser-induced fluorescence spectroscopy and antibacterial investigations. According to the P-XRD analysis, both the samples were simple cubic in structure and have average grain sizes of 54 and 28 nm, respectively. FE-SEM was deployed to explore the surface textures of the samples. EDX technique was used to look at the elemental compositions of the samples. The technique of FT-IR was employed to identify the vibrational modes. UV-Vis spectra in diffuse reflectance mode were obtained and the optical bandgaps of the CdO and Cu‒CdO samples were obtained as 4.52 eV and 2.83 eV, respectively. The photoluminescence studies were conducted at an excitation wavelength of 300 nm and emission peaks were red-shifted in both samples. Fluorescence spectroscopy was applied to explore the lifetimes of synthesized nanoparticles. The technique of Agar-well diffusion was applied to assess the antibacterial performance of the generated nanoparticles against Micrococcus Luteus (gram-positive) and Escherichia coli (gram-negative) bacterium at variable concentrations. Both samples in the current study are significantly effective against both bacterial strains.

Developing modifiable natural products those having antiviral activities against SARS-CoV-2 is a key research area which is popular in current scenario of COVID pandemic. A diaryl heptanoid curcumin and its derivatives are already presenting promising candidates for anti-viral drug development. We have synthesized single crystals of a dimethylamino derivative of natural curcumin and structural characterization was done by single crystal XRD analysis. Using steady-state absorption and emission spectra and guided by complimentary ab initio calculations, we unraveled the solvent effects on the photophysical properties of the dimethyl amino curcumin derivative. Chemical reactivity of the compound has investigated using frontier molecular orbitals and molecular electrostatic potential surface. High stability of the curcumin derivative in water environment has evaluated by Radial Distributions Functions (RDF) calculated via Molecular Dynamics (MD) simulations. The inhibitory activity of the title compound was evaluated by in silico methods and the stability of the protein-ligand complexes were studied using Molecular Dynamics simulations and MM-PBSA analysis. With this detailed study, we hope to motivate scientific community to develop new curcumin derivatives against SARS-CoV-2 virus.

7-Hydroxycoumarin\'s FT-IR solid phase spectra were observed at 4000-400 cm-1. The spectra were analyzed in aspects of significant approaches. DFT was used to optimize the structure of the compound and its structural properties. The molecular properties were also determined by the HF/3-21G level. The bond lengths and bond angles were obtained by the computational study of the optimized geometry. The vibrational frequencies were determined in all these approaches, which were then matched to experimental frequencies, yielding an excellent agreement between measured and estimated frequency ranges. The UV-visible spectrum of 7HC was obtained and the electronic characteristics HOMO and LUMO energies were monitored by the time-dependent TD-DFT method. The spectral behavior of 7-Hydroxycoumarin was studied using fluorescence spectroscopy in a wide range of polar and non-polar solvents. Solvatochromic effect was observed in both the fluorescence and absorption spectra. The structural properties, energies, IR intensities, absorption wavelengths, and harmonic vibrational frequencies were compared with the obtainable experimental information of the molecule.

Here in, we demonstrate a selective detection of Ag+ ion by the anthracene-based schiff base sensor AMC. The recognition event among sensor AMC and Ag+ ion was investigated by enhanced absorption band, red-shifted quenched emission spectra, electrochemical studies and DFT computational studies. The presence of Ag+ ion to solution of AMC quenched almost 50 % emission intensity of the ligand band. Data from high-resolution electrospray ionization mass spectrometry (ESI-HRMS), Ag+ titrations, and Job\'s plot studies all show that Ag+ binds to AMC in a 1:1 stoichiometric ratio.The quantitative parameters of sensor for silver ion are determined as the limit of detection (LOD) 5.95 × 10-7 M, and limit of quantitation (LOQ) 1.98 × 10-8 M in the linear range 3.48-20.31 × 10-6 M with good association affinity of 5.030 × 103 M-1. LMCT phenomenon from insilico studies, is in good agreement with the results obtained from other performed spectroscopic techniques. In addition, this sensor AMC was also successfully applied to real water samples for the identification and measurement of Ag+ ions.

Dye-sensitized solar cell\'s electron transport layer is responsible for transporting photo-generated electrons to the outer circuit. Utilizing localized surface plasmon resonance (SPR), light absorption could be enhanced to a greater degree, which can drive dye molecules to excited state more effectively than far-field light. In this work, TiO2 nanoparticles were prepared by solvothermal method, and Ag nanoparticles were decorated over TiO2 surface through photodeposition method. XRD data of the TiO2 sample exhibits anatase phase and in the Ag nanoparticle decorated TiO2 sample, peaks corresponding to (111) planes of Ag was observed. UV-Vis absorption analysis of the TiO2 and Ag decorated TiO2 samples showed absorption in the UV region for the TiO2, and the SPR effect was detected for the Ag deposited TiO2 samples. Ag nanoparticles decorated over TiO2 was observed to be spherical in shape through the images from transmission electron microscope. Presence of both Ag and AgO in the prepared sample was revealed through the data from X-ray photoelectron spectroscopy. The prepared material was used as photoanodes in the construction of the DSSCs, and their performance was evaluated.