International Journal Of Bio-Inorganic Hybrid Nanomaterials
Volume:4 Issue: 1, Spring 2015

Graphene, after its first production in 2004 have received lots of attentions from researchers because of its unique properties. High mobility, high sensitivity, high selectivity and high surface area make graphene excellent choice for bio application. One of promising graphene base device that has amazingly high sensitivity is graphene field-effect transistor (GFET). This review selectively summarizes the recent progress in fabrication and application of GFET for various biosensors. This article begins with short description and history of ion-sensitive field-effect transistor (ISFET). After that, advantages of graphene ISFET will be summarized. Then, GFET fabrication process including graphene sheet growth different methods, drain/source electrode deposition and lithography and passivation will be discussed. Finally, different application of GFET in detection of Deoxyribonucleic acid (DNA), pH and protein will be present and quality of GFET biosensor will be examined.

According to circumstance of kerman sarcheshmeh cooper complex that its anode slime is mainly consisted of Cu, Ag, Au, Pb and Se. In this work, recovery of silver from anode slime and subsequent synthesis of silver nanoparticles from leaching solution was made. Silver was separated from anode slime by using of HNO3 and HCl. X-Ray fluorescence spectroscopy (XRF) was used to characterize anode slime components. Silver nanoparticles (SNPs) with average size of 25 nm were obtained through sonication aqueous solution of silver nitrate in the presence of dextrose and polyvinyl pyrrolidone (PVP) as reduction and stabilizing agent respectively. SNPs were characterized by surface plasmon resonance (SPR) and Ultraviolet-Vis­ible (UV-Vis) spectrum. X-Ray diffraction (XRD) pattern confirmed the cubic morphology of metallic SNPs and energy dispersive X-Ray spectroscopy (EDS) spectrum showed peaks of silver free of impurity. Size and distribution of SNPs were determined by dynamic light scattering analysis (DLS) and scanning electron microscopy (SEM).

In recent years, utilization of chitosan /tripolyphosphate nanoparticles has been considered greatly as protein delivery vehicles. Effects of a variety of factors on final characteristics of nanoparticles have been studied by many investigators. Although, the objective of this study was to achieve smaller chitosan nano carriers via changing fabrication parameters such as pH and temperature and to elucidate their effect on the size and polydispersity of nanoparticles. Nanoparticles were produced by ionic gellation method and particle’s morphology was shown by field emission scanning electron microscopy (FE-SEM). The results show that with increasing pH value from 4.5 to 6, either poly dispersity or hydrodynamic diameter decreased significantly in a linear trend (R2= 0.94 for size and 0.99 for pdI data). Results of this study could be used for preparing protein loaded chitosan nanoparticles with small sizes in the range of below 120 nanometers which is sympathetic for drug delivery applications.

Plants are rich source of natural products used for centuries to cure various the plant-derived medicines are based upon the premise that they contain natural substances that can promote health and alleviate illness. Silver NPs represent material, which can be used as a potential antibacterial agent in medical applications and different commercial products due to its biological activity. Recently, silver NPs as well as various silver-based compounds containing ionic silver (Ag+), exhibiting high antimicrobial activity, have been synthesized. Due to its biological activity. This study aimed to determine the effect of silver nanoparticles combined with Taxus baccata L. In this study the use with Hydroalcohlic extract Taxus baccata L. of method maceration (soaking) was prepared. Also antibacterial/antifungal activities of Compounds (extract, AgNPs, mixture of extract with AgNPs) were tested against three Gram-negative bacteria Escherichia coli (ATCC33218), Acinetobacter baumannii (ATCC150504) and Klebsiella pneumoniae (ATCC1827) and Gram-positive bacteria Staphylococcus aureus (ATCC 25293) and also fungi Aspergillus oryzae (ATCC20423). This research combines the inherent antimicrobial activity of silver metals with the Taxus baccata extract, yielding antibacterial activity-enhanced AgNPs.

Nano-sized titanium dioxide TiO2 powder was successfully prepared from its precursor titanium (IV) chloride by a simple and new wet chemical method. TiCl4 were used as precursor in hydrogen peroxide, H2O2 and ethanol. This solution was then peptized using nitric acid and heated under reflux at 80°C. Their physico-chemical properties were then characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The TEM results showed that the size of as-synthesized TiO2 nanoparticles were in the range of 7-10 nm. The SEM images showed that the size of nanoparticles increased when the nanoparticles prepared in presence of nitric acid. The SEM images showed that the quality of annealed TiO2 nanoaprticles, increased when the nanoparticles synthesized without nitric acid. The crystal structure of the nanoparticles before and after annealing was done by XRD analysis. It was realized that the rutile phase was formed after heat treatment at 600°C. XRD pattern also showed that the size of annealed TiO2 nanoparticles increased from 20 to 50 nm when the nanoparticles prepared with nitric acid.

Nanocomposite of ZrO2/ZnO was prepared under ultrasonic irradiation by sol gel process from directly mixing Zirconium and Zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500°C for 3h in furnace. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4 and zinc acetate dihydrated was dissolved in de-ionized water. The FT-IR analysis and the XRD study were exhibited that the crystal structure and purity of the ZrO2/ZnO nanocomposite FESEM images was indicated the morphology and the average size of the NPs. The average size of the ZrO2/ZnO nanocomposite was determined 37 nm.

The physical adsorption of hydrogen sulfide and carbon dioxide gases on the zigzag (5,0) carbon nanotubes doped with nitrogen was investigated through the application of B3LYP/6-31G* at the level of theory on Gaussian 03 software. A variety of stable and high abundance structures of nitrogen doped carbon nanotubes were considered in order to study the interaction between the mentioned gases in different situations by taking rotates of sour gas molecules in the inner and outer walls. Features such as correction of energy adsorption, energy gap, dipole moment, charge distribution, conductors and energy barrier as well as the main parameters such as the gas adsorption energy on the nanotubes were obtained. The results suggest that the nitrogen atom in the structure of carbon nanotubes causes to increase the adsorption of hydrogen sulfide and carbon dioxide gases. Adsorption of hydrogen sulfide on the nanotubes is more effective than carbon dioxide. Moreover, for both gases the adsorption processes are thermodynamically favorable. These nanotubes can be economically used to separate sour gases from natural gases and to recover the sulfur.

Sr5Nb4O15 – Nb2O5 nanocomposites were synthesized in 2 and 4 M KOH aqueous solutions, via a non-stoichiometric 1:2 Sr:Nb molar ratio hydrothermal method at 160°C for 48 h (S1 and S2, respectively). Sr(NO3)2 and Nb2O5 were used as raw materials. The synthesized nanomaterials were characterized by powder X-Ray diffraction (PXRD) technique. It was found that Sr5Nb4O15 has been crystallized in hexagonal crystal structure with space group P-3m1. Nb2O5 lattice parameters were also found as a= 6.175 Å, b= 29.175 Å, and c= 3.93 Å and a= 12.73 Å, b= 5.56 Å, and c= 4.88 Å with γ= 105.1°, respectively for the orthorhombic and monoclinic crystal structures. The morphologies of the synthesized materials were studied by field emission scanning electron microscope (FESEM). The FESEM images showed that the S1 and S2 nanocomposites had flower and plate like structures, respectively. Ultraviolet–Visible (UV-Vis) spectra analyses showed that the synthesized nanocomposites had strong light absorption properties in the ultraviolet light region. FTIR spectra of the obtained nanomaterials were also studied. Cell parameter refinements of the synthesized nanocomposites were also investigated.