Aerosol-Assisted CVD-Grown PdO Nanoparticle-Decorated Tungsten Oxide Nanoneedles Extremely Sensitive and Selective to Hydrogen

We report for the first time the successful synthesis of palladium (Pd) nanoparticle (NP)-decorated tungsten trioxide (WO3) nanoneedles (NNs) via a two-step aerosol-assisted chemical vapor deposition approach. Morphological, structural, and elemental composition analysis revealed that a Pd(acac)2 precursor was very suitable to decorate WO3 NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H2) gas sensor (sensor response peaks at 1670 at 500 ppm of H2) with low operating temperature (150 °C). The response of decorated NNs is 755 times higher than that of bare WO3 NNs. Additionally, at a temperature near that of the ambient temperature (50 °C), the response of this sensor toward the same concentration of H2 was 23, which is higher than that of some promising sensors reported in the literature. Finally, humidity measurements showed that PdO/WO3 sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO3 sensors. The addition of PdO NPs helps to minimize the effect of ambient humidity on the sensor response

Tin(IV) complexes with salen type Schiff base:synthesis, spectroscopic characterization, crystal structure, antibacterial screening and cytotoxicity

A series of six tin(IV) complexes [SnCl2(L) (I), Me2Sn(L) (II), Bu2Sn(L) (III), Ph2Sn(L) (IV), Oct2Sn(L) (V), BuSnCl(L) (VI)] derived from N,N'-bis(2-hydroxy-1-naphthylidene)-1,2-diaminobenzene [LH2] have been synthesized. The obtained compounds were characterized by elemental analysis, mass spectrometry, FT-IR and NMR (1H, 13C) spectroscopy. The crystal structures of compounds (IV) and (VI) have also been determined by single crystal X-ray analysis (CIF files CCDC nos. 856596 (IV) and 856595 (VI)). The study revealed that the complexes exist as discrete monomeric species and the tin atom is hexa-coordinated in a distorted octahedral geometry. The two phenyl groups in compound (IV) are at trans-positions. Similarly, in complex (VI) the butyl and chloro groups also adopt trans-orientation. The in vitro antibacterial screening and cytotoxicity investigations revealed that the biological activities significantly depend upon the alkyl or others groups present on tin atom. Most of the tin(IV) complexes are active against Escherichia coli and highest activity is shown by complex (IV) against Bacillus subtilis. Furthermore, complex (IV) has also demonstrated the highest cytotoxicity against brine shrimp with LD50 value 0.858 μg/mL

Structural characterization, DNA binding study, antioxidant potential and antitumor activity of diorganotin(IV) complexes against human breast cancer cell line MDA-MB-231

Five new organotin(IV) complexes, Me2SnL (1), n-Bu2SnL (2), tert-Bu2SnL (3), Ph2SnL (4) and n-Oct2SnL (5), have been synthesized from the reaction of R2SnCl2 (R= Me, Bu, tert-Bu, Ph, Oct) with N'-(3-ethoxy-2-hydroxybenzylidene)formohydrazide (H2L). The structural elucidation of synthesized compounds was done by FT-IR, 1H-NMR, 13C-NMR spectroscopy and single-crystal X-ray analysis. Crystallographic data of complex (1) showed seven coordinated central tin atom with distorted pentagonal bipyramidal geometry. Where in solution the Sn atom of synthesized complexes exhibit five coordination, confirmed from 1H-NMR. The results from DNA interaction studies via UV-visible spectroscopy, viscosity, cyclic voltammetry, and differential pulse voltammetry (DPV) suggested an intercalative mode of interaction between the synthesized compounds and SS-DNA. Furthermore, the complexes interact more significantly than ligand. Electrochemical and thermodynamic parameters, including diffusion coefficient, ∆H, ∆G, and ∆S, were calculated using cyclic voltammetry data. The linear plot of peak current (I) vs. square root of the scan rate (υ1/2) indicated the electrochemical processes to be diffusion controlled. The DPPH free radical scavenging assay results showed that complex (4) is an active antioxidant. In-vitro cytotoxicity of the synthesized compounds was determined on human breast cancer cell line MDA-MB-231 using tetrazolium-based MTT assay, and complexes (2), (3) and (4) showed significant cytotoxic activity. The structure-activity relationships may be utilised to direct the optimization of the activity of agents from this class of compounds by comparing the specifics of the compound structures, their DNA binding, and toxicity

Micromeria biflora mediated gold and silver nanoparticles for colourimetric detection of antibiotics and dyes degradation

The study reports on synthesis of aqueous extract mediated gold and silver nanoparticles of M. biflora (MBAuNPs and MBAgNPs) via hydrated chloroauric acid and silver nitrate salts. The nanoparticles (NPs) were produced in 1:15 (MBAuNPs) and 1:6 (MBAgNPs) ratios under sunlight displaying localized surface plasmon resonance (LSPR) peaks at 541 and 431 nm, respectively. The sizes characterized by transmission electron, scanning electron, and atomic force microscopic (SEM, TEM, AFM) techniques were respectively 26.73 nm and 53.81 nm. The subject NPs demonstrated application in the degradation of methylene blue, Congo red, Rhodamine B, methyl orange, ortho-nitrophenol, and para-nitrophenol ranging from 65 to 86 %. For detection of levofloxacin, amoxicillin, and azithromycin antibiotics, the MBAuNPs and MBAgNPs exhibited efficiency in real water and biological (blood plasma and urine) samples. Conclusively, the MBAuNPs and MBAgNPs applications for dyes degradation and antibiotics detection was found as simple and cost-effective analytical method

Aerosol-Assisted CVD-Grown PdO Nanoparticle-Decorated Tungsten Oxide Nanoneedles Extremely Sensitive and Selective to Hydrogen

We report for the first time the successful synthesis of palladium (Pd) nanoparticle (NP)-decorated tungsten trioxide (WO₃) nanoneedles (NNs) via a two-step aerosol-assisted chemical vapor deposition approach. Morphological, structural, and elemental composition analysis revealed that a Pd­(acac)₂ precursor was very suitable to decorate WO₃ NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H₂) gas sensor (sensor response peaks at 1670 at 500 ppm of H₂) with low operating temperature (150 °C). The response of decorated NNs is 755 times higher than that of bare WO₃ NNs. Additionally, at a temperature near that of the ambient temperature (50 °C), the response of this sensor toward the same concentration of H₂ was 23, which is higher than that of some promising sensors reported in the literature. Finally, humidity measurements showed that PdO/WO₃ sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO₃ sensors. The addition of PdO NPs helps to minimize the effect of ambient humidity on the sensor response