Tariq Iqbal

Copper Ion Beam Irradiation-Induced Effects on Structural, Morphological and Optical Properties of Tin Dioxide Nanowires*

The 0.8 MeV copper (Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (SnO2 NWs) are investigated. The samples are irradiated at three different doses 5 × 1012 ions/cm2, 1 × 1013 ions/cm2 and 5 × 1013 ions/cm2 at room temperature. The XRD analysis shows that the tetragonal phase of SnO2 NWs remains stable after Cu ion irradiation, but with increasing irradiation dose level the crystal size increases due to ion beam induced coalescence of NWs. The FTIR spectra of pristine SnO2 NWs exhibit the chemical composition of SnO2 while the Cu—O bond is also observed in the FTIR spectra after Cu ion beam irradiation. The presence of Cu impurity in SnO2 is further confirmed by calculating the stopping range of Cu ions by using TRM/SRIM code. Optical properties of SnO2 NWs are studied before and after Cu ion irradiation. Band gap analysis reveals that the band gap of irradiated samples is found to decrease compared with the pristine sample. Therefore, ion beam irradiation is a promising technology for nanoengineering and band gap tailoring.

In vitro Studies on Cytotoxic, DNA Protecting, Antibiofilm and Antibacterial Effects of Biogenic Silver Nanoparticles Prepared with Bergenia ciliata Rhizome Extract

BACKGROUND Many health hazardous diseases are caused by clinical pathogens. Drugresistant microbes are one of the major health problems in the world. To overcome the effect of infectious diseases new antimicrobial agent from nature has been explored which is environmentally friendly, less costly and more effective for the development of next-generation drugs. Bergenia ciliata and silver nitrate both have medicinal properties. OBJECTIVES The aim of the current research was to evaluate the cytotoxic, and antibacterial effect of green synthesized nanoparticles using Bergenia ciliata rhizome against clinical bacterial pathogens. METHODS Extract of Bergenia ciliata was prepared by maceration technique. Silver nanoparticles were synthesized using Bergenia ciliata rhizome extract. Synthesized silver nanoparticles were confirmed by UV-vis spectrophotometer, Scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The antibacterial, anti-biofilm, cell proliferation inhibition, DNA protection, brine shrimp lethality effects of synthesized nanoparticles were investigated. RESULTS UV-vis spectrophotometer indicated the prelaminar synthesis of silver nanoparticles at 400 nm. The spherical shape of synthesized nanoparticles with 35 nm size was confirmed using SEM. Greatest zone of inhibition (6.0 ± 0.0 mm to 8.3 ± 0.57 mm) was recorded against all tested pathogens compared with the B. ciliata aqueous extract. Anti-biofilm analysis and MTT assay supported the results of the antibacterial activity. Silver nanoparticles protect the DNA degradation. CONCLUSION Green synthesized nanoparticles had potent antibacterial activity and may provide a basis for the development of the new antibacterial drug.

Atmospheric pressure microplasma assisted growth of silver nanosheets and their inhibitory action against bacteria of clinical interest

Two-dimensional staggered silver nanosheets were synthesized using a facile atmospheric microplasma electrochemical process at room temperature. It is an environmental friendly technique that does not include toxic reducing agents. In this technique, microplasma directly reduces Ag+ ions into an electrolyte solution. The synthesized silver nanosheets were investigated by scanning electron microscope, x-ray diffraction, ultraviolet–visible spectroscopy and fourier transform infrared spectroscopy. This type of morphology has not yet been reported using a microplasma technique. The antibacterial activity of the as-synthesized nanosheets against Klebsiella pneumoniae, the Staphylococcus strain, Escherichia coli and Acinetobacter was carried out using a disc diffusion method. The results indicated that these sheets show significant antibacterial activity against Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli and Acinetobacter compared with that of the standard antibiotic.

Influence of Temperature on the Morphology and Grain Size of Cupric Oxide (CuO) Nanostructures via Solvothermal Method

Cupric oxide (CuO) nanostructures have been synthesized successfully through solvothermal chemical route. The influence of temperature on the morphology and the grain size of CuO have been investigated. Phase analysis of synthesized CuO has also been carried out using X-ray diffraction (XRD). XRD peaks showed the monoclinic crystalline phase of CuO nanostructures. The morphology of CuO has been studied by using Scanning Electron Microscope (SEM). SEM images showed the rod-like and sheet-like morphology of CuO. Fourier Transform Infrared (FTIR) spectroscopy has been employed to study the vibrational modes. The FTIR spectra confirmed the stretching vibrations of Cu-O bond. In addition, UV-visible absorption spectra have been implemented to estimate the energy bandgap of the synthesized CuO nanostructures. The energy bandgap of as prepared CuO nanostructures was estimated between 2.0 eV to 2.52 eV. The grain size was found to be increasing with the rise in temperature. The increase in grain size with increasing temperatures causes the reduction in the bandgap, which is attributed to the quantum confinement effect at smaller particle size.

Solvothermal synthesis of luminescent bis-(8 hydroxy quinoline) cadmium complex nanostructures

A facile solution- based route for the synthesis of Bis- (8- hydroxyquinoline) Cadmium (CdCh) complex nanorods, nanoflowers (bundles of nanorods) and nanosheets in an oleic acid- sodium oleate- ethanol- H2O system at 50°C -100°C was reported. Scanning Electron Microscope (SEM) images indicated that longer time and higher temperature would result in nanoflowers, while lower temperature and shorter reaction time would be suitable for the formation of nanorods. However, a novel change in these structures was observed when the concentration of the surfactant (oleic acid) was reduced and we obtained 2- D nanosheets. Fourier- transform infrared (FTIR) spectroscopy was utilized to confirm that the samples were made up of CdQ2. UV/ VIS spectroscopy was used to determine the different electronic transitions in CdQ2 molecule. All the samples possessed excellent photoluminescence (PL) properties. Photoluminescence (PL) spectra showed a prominent peak around 500 nm which indicated a strong PL emission in the green region. This methodology could be extended for the controlled, large- scale preparation of other functional complexes, and the obtained nanostructures could be introduced as the basic building blocks for novel optoelectronic devices.