RESUMO
Novel push-pull fluorescent molecules based on dicyanodihydrofuran that had marked molar extinction coefficients were created and described. The fluorophores were synthesized using the Knoevenagel condensation in arid pyridine at room temperature and acetic acid as a catalytic agent. In addition, a condensation reaction was performed for the activated methyl-containing dicyanodihydrofuran with a 3° amine-containing aromatic aldehyde. The molecular structures for the synthesized fluorophores were determined using various spectral techniques such as 1 H or 13 C nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, and C, H, N analysis. Ultraviolet-visible (UV-vis) absorption and emission spectra of the prepared fluorophores revealed a high extinction coefficient, which was monitored to be affected by the type of the aryl (phenyl and thiophene)-vinyl bridge in conjugation with the 3° amine donor moiety. The substituents bonded to the tertiary amine, aryl, and alkyl groups, were found to affect the maximum absorbance wavelength. In addition, the synthesized dicyanodihydrofuran analogues were investigated to determine their antimicrobial effectiveness. Derivatives 2b, 4a, and 4b showed reasonable activity towards Gram-positive(+ve) bacteria rather than Gram-negative(-ve) bacteria relative to an amoxicillin drug reference. In addition, a molecular docking stimulation was performed to explore the binding interactions (PDB code: 1LNZ).
Assuntos
Antibacterianos , Corantes Fluorescentes , Simulação de Acoplamento Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/farmacologia , Antibacterianos/química , Corantes Fluorescentes/farmacologia , Corantes Fluorescentes/química , Estrutura MolecularRESUMO
Recently, the active surface modification of glassy carbon electrodes (GCE) has received much attention for the development of electrochemical sensors. Nanomaterials are widely explored as surface-modifying materials. Herein, we have reported the hydrothermal synthesis of molybdenum disulfide (MoS2) and its electro-catalytic properties for the fabrication of a resorcinol sensor. Structural properties such as surface morphology of the prepared MoS2 was investigated by scanning electron microscopy and phase purity was examined by employing the powder X-ray diffraction technique. The presence of Mo and S elements in the obtained MoS2 was confirmed by energy-dispersive X-ray spectroscopy. Finally, the active surface of the glassy carbon electrode was modified with MoS2. This MoS2-modified glassy carbon electrode (MGC) was explored as a potential candidate for the determination of resorcinol. The fabricated MGC showed a good sensitivity of 0.79 µA/µMcm2 and a detection limit of 1.13 µM for the determination of resorcinol. This fabricated MGC also demonstrated good selectivity, and stability towards the detection of resorcinol.
RESUMO
Cellulose nanoparticles are sustainable natural polymers with excellent application in environmental remediation technology. In this work, we synthesized cellulose nanoparticles and covalently functionalized them with a multi-functional group possessing ligands. The hybrid material shows excellent adsorption properties for the simultaneous extraction of multiple metal ions in the sample preparation technique. The sorbent shows excellent sorption capacity in the range of 1.8-2.2 mmol/g of material. The developed method was successfully employed for the simultaneous extraction of Pb(II), Cd(II) and Cu(II) from real-world samples (industrial effluent, river water, tap and groundwater) and subsequently determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). The method shows a preconcentration limit of 0.7 ppb attributes to analyze the trace concentration of studied metal ions. The detection limit obtained for Pb(II), Cd(II) and Cu(II) is found to be 0.4 ppb.
RESUMO
Herein, we reported the simulation study of lead (Pb)-free all-perovskite tandem solar cells using SCAPS-1D. Tandem solar cells are comprised of two different cells which are known as the top cell and the bottom cell. We simulated tandem solar cells using methyl ammonium germanium iodide (MAGeI3) as the top subcell absorber layer due to its wide band gap of 1.9 eV. Further, FA0.75MA0.25Sn0.25Ge0.5I3 = FAMASnGeI3 was used as the bottom subcell absorber layer due to its narrow band gap of 1.4 eV. The tandem solar cells were simulated with MAGeI3 as the top cell and FAMASnGeI3 as the bottom subcell using SCAPS-1D. Various electro-transport layers (ETLs) i.e., titanium dioxide, tin oxide, zinc oxide, tungsten trioxide, and zinc selenide, were used to examine the impact of ETL on the efficiency of tandem solar cells. The observations revealed that TiO2 and ZnSe have more suitable band alignment and better charge-extraction/transfer properties. A reasonably improved efficiency of 23.18% and 22.4% have been achieved for TiO2 and ZnSe layer-based tandem solar cells, respectively.
RESUMO
A graphene oxide (GO/CdS) nanocomposite was synthesized by an in situ hydrothermal process and studied to develop a micro solid phase extraction procedure. Microscopic and spectroscopic characterizations have confirmed the successful preparation of the GO/CdS composite. The prepared nanocomposite selectively extracts Hg(II) ions from various water samples (tap, river, and groundwater). The intriguing characteristic of GO sheets is to provide exceptional hydrophilicity and Hg(II) accessibility to surface-decorated CdS nanoparticles. The GO/CdS nanocomposite shows excellent extraction of trace Hg(II) in a short interval of time. Computations based on density functional theory (DFT) suggest that energetically favorable multinuclear S-Hg binding leads to rapid adsorption with high sorption capacity at GO/CdS sites. The analytical features of merit suggested that the developed method has a low detection limit (0.07 µg L-1) and shows good accuracy and precision (with RSD 3.5%; N = 5). The developed method was verified by analyzing SRM 1641d (Standard Reference Material) and real samples after spiking to a predetermined amount.