Materials with nonlinear optical (NLO) properties have significant applications in different fields, including nuclear science, biophysics, medicine, chemical dynamics, solid physics, materials ...science and surface interface applications. Quinoline and carbazole, owing to their electron-deficient and electron-rich character respectively, play a role in charge transfer applications in optoelectronics. Therefore, an attempt has been made herein to explore quinoline-carbazole based novel materials with highly nonlinear optical properties. Structural tailoring has been made at the donor and acceptor units of two recently synthesized quinoline-carbazole molecules (
Q1
,
Q2
) and acceptor-donor-π-acceptor (A-D-π-A) and donor-acceptor-donor-π-acceptor (D-A-D-π-A) type novel molecules
Q1D1-Q1D3
and
Q2D2-Q2D3
have been quantum chemically designed, respectively. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) computations are performed to process the impact of acceptor and donor units on photophysical, electronic and NLO properties of selected molecules. The
λ
max
values (321 and 319 nm) for
Q1
and
Q2
in DSMO were in good agreement with the experimental values (326 and 323 nm). The largest shift in absorption maximum is displayed by
Q1D2
(436 nm). The designed compounds (
Q1D3-Q2D3
) express absorption spectra with an increased border and with a reduced band gap compared to the parent compounds (
Q1
and
Q2
). Natural bond orbital (NBO) investigations showed that the extended hyper conjugation and strong intramolecular interaction play significant roles in stabilising these systems. All molecules expressed significant NLO responses. A large value of
β
tot
was elevated in
Q1D2
(23 885.90 a.u.). This theoretical framework reveals the NLO response properties of novel quinoline-carbazole derivatives that can be significant for their use in advanced applications.
Materials with nonlinear optical properties have significant applications in nuclear science, biophysics, medicine, chemical dynamics, solid physics & materials science. We show how π bridges, donors & acceptors can be reconfigured to improve optical properties.
Considering the increased demand and potential of photovoltaic devices in clean, renewable electrical and hi-tech applications, non-fullerene acceptor (NFA) chromophores have gained significant ...attention. Herein, six novel NFA molecules IBRD1-IBRD6 have been designed by structural modification of the terminal moieties from experimentally synthesized A2-A1-D-A1-A2 architecture IBR for better integration in organic solar cells (OSCs). To exploit the electronic, photophysical and photovoltaic behavior, density functional theory/time dependent-density functional theory (DFT/TD-DFT) computations were performed at M06/6-311G(d,p) functional. The geometry, electrical and optical properties of the designed acceptor molecules were compared with reported IBR architecture. Interestingly, a reduction in bandgap (2.528-2.126 eV), with a broader absorption spectrum, was studied in IBR derivatives (2.734 eV). Additionally, frontier molecular orbital findings revealed an excellent transfer of charge from donor to terminal acceptors and the central indenoindene-core was considered responsible for the charge transfer. Among all the chromophores, IBRD3 manifested the lowest energy gap (2.126 eV) with higher λ
at 734 and 745 nm in gaseous phase and solvent (chloroform), respectively due to the strong electron-withdrawing effect of five end-capped cyano groups present on the terminal acceptor. The transition density matrix map revealed an excellent charge transfer from donor to terminal acceptors. Further, to investigate the charge transfer and open-circuit voltage (V
), PBDBT donor polymer was blended with acceptor chromophores, and a significant V
(0.696-1.854 V) was observed. Intriguingly, all compounds exhibited lower reorganization and binding energy with a higher exciton dissociation in an excited state. This investigation indicates that these designed chromophores can serve as excellent electron acceptor molecules in organic solar cells (OSCs) that make them attractive candidates for the development of scalable and inexpensive optoelectronic devices.
In this study, zinc oxide nanoparticles (ZnO NPs) were fabricated using Equisetum diffusum D extract and their diverse properties and applications were studied. Phytochemical analysis confirmed the ...presence of phenols and flavonoids in the plant extract, playing a crucial role in the stabilization and reduction of the synthesized nanoparticles. The greenly synthesized ZnO NPs were characterized through a range of analytical techniques. UV-visible spectrophotometry has been employed to investigate their optical characteristics. FTIR spectroscopy was employed to identify the functional groups responsible for the synthesis of the ZnO NPs. The structural properties were evaluated using XRD. The morphology and size distribution of the synthesized NPs were examined using SEM, DLS, and elemental spectra evaluated using EDX. The charge that develops at the interface was analyzed using zeta potential which accounts for stability of the NPs. The ZnO NPs exhibited excellent photocatalytic degradation of cationic (methylene blue), anionic (methyl orange), and nonionic ( p -nitrophenol) dyes under sunlight exposure with photocatalytic degradation of 85.61%, 79.10%, and 89.95% respectively. Additionally, the nanoparticles displayed antimicrobial activity against Gram-positive and Gram-negative bacteria, and noteworthy antioxidant potential. The anti-inflammatory activity of the ZnO NPs, attributed to their ability to inhibit protein denaturation, was dose-dependent. Overall, our findings highlight the versatile properties of the greenly synthesized ZnO NPs, showcasing their potential in environmental remediation, and antimicrobial formulations, and as promising candidates for further exploration in the biomedical fields, including drug delivery and therapeutics.
Display omitted
•Electrochemical biosensor with structure AChE/N-CD/BSA/PGE was constructed.•N-CD/BSA nanocomposite augmented catalytic ability and immobilization of the enzyme.•Biosensor can ...promptly detect honey bee Acetylcholinesterase inhibition by Diazinon.•Diazinon detection from wheat samples proves good reliability of proposed method.•Molecular docking analysis of enzyme and inhibitor verified experimental findings.
This work describes the development and optimization of an electrochemical method to evaluate pesticide induced inhibition of honey bee (Apis mellifera) acetylcholinesterase (AChE) by means of acetylcholinesterase biosensor. The inhibition assay was based on the detection of changes in electrochemical activity of the enzyme caused by pesticide. As transducer, nitrogen doped carbon dots BSA (N-CD/BSA) nanocomposite electrodeposited on pencil graphite electrode was used to covalently immobilize AChE. The as-synthesized nanocomposite and fabricated electrodes were characterized for the structural, functional and electrochemical properties. Nanocomposite promoted the electron transfer reaction to catalyze the electro-oxidation of thiocholine and a large current response was obtained by cyclic voltammetry at 0.77 V, indicating successful immobilization of AChE. The sensitivity of Diazinon, an OP insecticide, for honeybee AChE was tested under optimal conditions and a linear response ranging 10–250 nM was obtained with a detection limit of 8.9 nM, and sensitivity 9 uA/nM/cm2. The method showed a good operational reproducibility and selectivity of biosensor. Further, the molecular docking provided additional support to the experimental data suggesting irreversible nature and contact toxicity of the pesticide for honey bee AChE. The developed biosensor has proved useful for the diazinon detection in wheat samples with 99% recovery rate.
•WO3/g-C3N4 was used to construct a novel AChE/PGE biosensor.•Biosensor permitted to detect Phosmet with a detection limit of 3.6 nM.•The developed biosensor showed recovery between 92 and 99% for ...wheat samples.•In vivo repellency bioassay determined the efficacy of Phosmet against T. castaneum.•Computational analysis explored the structural topographies for enzyme-inhibitor interaction.
This study was undertaken to assess the potential of Tribolium castaneum (Red flour beetle) acetylcholinesterase (Tc-AChE) based electrochemical biosensor integrating WO3/g-C3N4 nanocomposite modified Pencil graphite electrode to detect an organophosphate insecticide, Phosmet. The WO3/g-C3N4 nanocomposite provides a non-toxic, biocompatible surface for binding the enzyme on the electrode surface, attributed to its large surface area, high conductivity, and low ohmic resistance. The proposed biosensor shows a very good analytical performance with LOD 3.6 nM for Phosmet and effectively determined Phosmet in wheat with a 99% recovery rate. Furthermore, molecular docking deciphers the binding interactions of Phosmet with Tc-AChE using a modified AutoDock LGA algorithm and an AMBER03 force field in YASARA. The kinetic parameters strongly suggest the high potency of inhibitor with the enzyme. This study presents an adaptable, rapid, and straightforward approach that opens ways towards real progress in developing commercial biosensors for pesticide detection.
A donor-π-acceptor type series of Triphenylamine-dicyanovinylene-based chromophores (
) was designed theoretically by the structural tailoring of π-linkers of experimentally synthesized molecules
and
...to exploit changes in the optical properties and their nonlinear optical materials (NLO) behaviour. Density functional theory (DFT) computations were employed to understand the electronic structures, absorption spectra, charge transfer phenomena and the influence of these structural modifications on NLO properties. Interestingly, all investigated chromophores exhibited lower band gap (2.22-2.60 eV) with broad absorption spectra in the visible region, reflecting the remarkable NLO response. Furthermore, natural bond orbital (NBO) findings revealed a strong push-pull mechanism in
as donor and π-conjugates exhibited positive, while all acceptors showed negative values. Examination of electronic transitions from donor to acceptor moieties via π-conjugated linkers revealed greater linear (〈
〉 = 526.536-641.756 a.u.) and nonlinear (
= 51 313.8-314 412.661 a.u.) response. It was noted that the chromophores containing imidazole in the second p-linker expressed greater hyperpolarizability when compared with the ones containing pyrrole. This study reveals that by controlling the type of π-spacers, interesting metal-free NLO materials can be designed, which can be valuable for the hi-tech NLO applications.
This article presents an optimized ultrasound‐assisted ethanolic extraction (UAEE) and characterization of selected high‐value components from Gemlik olive fruit (GOF) harvested from Potohar region ...of Pakistan. Response surface methodology (RSM), involving central composite design (CCD), was applied to optimize the extraction variables i. e., temperature (25–65 °C), extraction time (15–45 min) and aqueous ethanol concentration (60–90 %) for optimal recovery of bioactives extract, total phenolic contents (TPC) and DPPH free radical scavengers. Under the optimized set of conditions such as 43 °C temperature, 32 min extraction time and 80 % aqueous ethanol, the best extract yield (218.82 mg/g), TPC (19.87 mg GAE/g) and DPPH scavenging activity (63.04 %) were recorded. A quadratic polynomial model was found to be reasonably fitted to the observed results for extract yield (p<0.0001 and R2=0.9941), TPC (p<0.0001 and R2=0.9891), and DPPH radical scavenging activity (p<0.0001 and R2=0.9692). Potent phenolic compounds were identified by GC/MS in GOF extract and considerable amount of essential fatty acids were also detected. The current findings support the use of UAEE as an effective green route for optimized recovery of high‐value components from GOF and hence its applications can be extended to functional food and nutra‐pharmaceutical developments.
Organic materials development, especially in terms of nonlinear optical (NLO) performance, has become progressively more significant owing to their rising and promising applications in potential ...photonic devices. Organic moieties such as carbazole and quinoline play a vital role in charge transfer applications in optoelectronics. This study reports and characterizes the donor-acceptor-donor-π-acceptor (D-A-D-π-A) configured novel designed compounds, namely,
-
,
-
, and
. We further analyze the structure-property relationship between the quinoline-carbazole compounds for which density functional theory (DFT) and time-dependent DFT (TDDFT) calculations were performed at the B3LYP/6-311G(d,p) level to obtain the optimized geometries, natural bonding orbital (NBO), NLO analysis, electronic properties, and absorption spectra of all mentioned compounds. The computed values of λ
, 364, 360, and 361 nm for
,
, and
show good agreement of their experimental values: 349, 347, and 323 nm, respectively. The designed compounds (
-
) exhibited a smaller energy gap with a maximum redshift than the reference molecules (
-
), which govern their promising NLO behavior. The NBO evaluation revealed that the extended hyperconjugation stabilizes these systems and caused a promising NLO response. The dipole polarizabilities and hyperpolarizability (β) values of
-
,
-
, and
exceed those of the reference
,
, and
molecules. These data suggest that the NLO active compounds,
-
,
-
, and
, may find their place in future hi-tech optical devices.
The present work reports the synthesis, characterization, and antimicrobial activities of adipic acid-capped silver nanoparticles (AgNPs@AA) and their utilization for selective detection of Hg
ions ...in an aqueous solution. The AgNPs were synthesized by the reduction of Ag
ions with NaBH
followed by capping with adipic acid. Characterization of as-synthesized AgNPs@AA was carried out by different techniques, including UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Dynamic Light Scattering (DLS), and zeta potential (ZP). In the UV-Vis absorption spectrum, the characteristic absorption band for AgNPs was observed at 404 nm. The hydrodynamic size of as-synthesized AgNPs was found to be 30 ± 5.0 nm. ZP values (-35.5 ± 2.4 mV) showed that NPs possessed a negative charge due to carboxylate ions and were electrostatically stabilized. The AgNPs show potential antimicrobial activity against clinically isolated pathogens. These AgNPs were found to be selectively interacting with Hg
in an aqueous solution at various concentrations. A calibration curve was constructed by plotting concentration as abscissa and absorbance ratio (A
- A
/A
) as ordinate. The linear range and limit of detection (LOD) of Hg
were 0.6-1.6 μM and 0.12 μM, respectively. A rapid response time of 4 min was found for the detection of Hg
by the nano-probe. The effect of pH and temperature on the detection of Hg
was also investigated. The nano-probe was successfully applied for the detection of Hg
from tap and river water.
The mucus layers of fish serve as the main interface between the organism and the environment. They play an important biological and ecological role. The current study focuses on Nile tilapia ...epidermal mucus reared under different commercial feeds (coded A and B) and environments (biofloc technology and earthen pond systems). Crude protein levels in feed A and B were 30% and 28%, respectively. Water parameters in all culturing systems were suitable for tilapia throughout the study period. The antimicrobial potency of tilapia (n = 5 from each) epidermal mucus was tested in vitro against human and fish pathogenic strains viz. Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Francisella noatunensis, and Aeromonas hydrophila. To determine the antimicrobial activity, zones of inhibition (ZOI) were measured in millimetres and compared with two antibiotics (chloramphenicol and ciprofloxacin). SDS-PAGE analysis was performed on skin mucus samples of tilapia to determine protein quantity and size (molecular weight). Results of tilapia skin mucus (crude and aqueous) revealed a strong antibacterial effect against all the selected pathogenic strains. However, variation has been observed in the mucus potency and ZOI values between the biofloc and pond tilapia mucus. The crude mucus of tilapia fed on feed A and cultured in the pond exhibited strong antibacterial effects and high ZOI values compared to the mucus of biofloc tilapia, aqueous mucus extracts and positive control chloramphenicol (antibiotic). The SDS-PAGE results showed that the high molecular weight proteins were found in the collected epidermal mucus of BFT-B (240 kDa) and EP-B (230 kDa). Several peptides in fish skin mucus may play a crucial role in the protection of fish against disease-causing pathogens. Thus, it can be utilized in the human and veterinary sectors as an 'antimicrobial' for treating various bacterial infections.
PDF
