Mohd Zobir Hussein

Cytotoxicity of nickel zinc ferrite nanoparticles on cancer cells of epithelial origin

In this study, in vitro cytotoxicity of nickel zinc (NiZn) ferrite nanoparticles against human colon cancer HT29, breast cancer MCF7, and liver cancer HepG2 cells was examined. The morphology, homogeneity, and elemental composition of NiZn ferrite nanoparticles were investigated by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The exposure of cancer cells to NiZn ferrite nanoparticles (15.6–1,000 μg/mL; 72 hours) has resulted in a dose-dependent inhibition of cell growth determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The quantification of caspase-3 and -9 activities and DNA fragmentation to assess the cell death pathway of the treated cells showed that both were stimulated when exposed to NiZn ferrite nanoparticles. Light microscopy examination of the cells exposed to NiZn ferrite nanoparticles demonstrated significant changes in cellular morphology. The HepG2 cells were most prone to apoptosis among the three cells lines examined, as the result of treatment with NiZn nanoparticles. In conclusion, NiZn ferrite nanoparticles are suggested to have potential cytotoxicity against cancer cells.

Electrodeposited SnS thin films from aqueous solution

Considerable efforts have been made in recent years in the search for low-cost materials for solar energy conversion. Among the materials of great interest are polycrystalline metal chalcogenides. These can be synthesized by means of low-temperature chemical precipitation or vapour deposition techniques, as described in previous works [1, 2]. The materials may also be electrosynthesized, either cathodically [3‐5] or anodically [6‐8] from an aqueous or nonaqueous medium. Electrochemical methods, especially those performed in an aqueous medium, have recently received enormous attention due to their simplicity and cost effectiveness [9‐15]. In addition, they have the advantages of being low temperature processes, with low material wastage and with the possibility of using lower grade materials. This method has been extensively applied in the preparation of CdS and CdSe thin films. We report here the possibility of cathodic electrodeposition of another promising compound, tin sulphide (SnS), from aqueous solution. The electrodeposition was carried out on either titanium or an indium-doped tin oxide (ITO) glass substrate in a standard three-electrode cell. A saturated calomel electrode (SCE) or sometimes an Ag AgCl electrode was used as the reference electrode, while platelet or spiral Pt (99.9%) was used as the counter electrode. The deposition potential was controlled by an EG&G Princeton Applied Research (PAR) Versastat driven by model 270 Electrochemical Analysis System software. The substrate was polished and chemically and ultrasonically cleaned before being used. The electrodeposition bath was prepared from anhydrous SnCl2, sodium thiosulphate (Na2S2O3) and disodium ethylenediaminetetra-acetic acid (EDTA) salts using N2purged purified water from a Milli-Q water purification system. The resultant solution was acidified to a pH of about 1.5. The solution was continuously deaerated with N2 during electrodeposition. Prior to electrodeposition, cyclic voltammetry was run in order to determine the viable potential and to elucidate the electrochemical processes at the

Facile synthesis of calcium carbonate nanoparticles from cockle shells

A simple and low-cost method for the synthesis of calcium carbonate nanoparticles from cockle shells was described. Polymorphically, the synthesized nanoparticles were aragonites which are biocompatible and thus frequently used in the repair of fractured bone and development of advanced drug delivery systems, tissue scaffolds and anticarcinogenic drugs. The rod-shaped and pure aragonite particles of 30 ± 5 nm in diameter were reproducibly synthesized when micron-sized cockle shells powders were mechanically stirred for 90 min at room temperature in presence of a nontoxic and nonhazardous biomineralization catalyst, dodecyl dimethyl betaine (BS-12). The findings were verified using a combination of analytical techniques such as variable pressure scanning electron microscopy (VPSEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray analyser (EDX). The reproducibility and low cost of the method suggested that it could be used in industry for the large scale synthesis of aragonite nanoparticles from cockle shells, a low cost and easily available natural resource.

Oil Palm Trunk as a Raw Material for Activated Carbon Production

Oil palm trunk is a major lignocellulosic-rich, solid waste material generated from palm-oil upstream industry. The activated carbons prepared from oil palm trunk pretreated with phosphoric acid with the ratio of the acid to the precursor of 0.9, followed by carbonization and activation by carbon dioxide resulted in a high surface area of more than 1800 m2/g with 90% content of micropore surface area. The surface area and the nature of the porosity of the resulting activated carbons were found to be dependent on the amount of the activator used for a fixed quantity of the precursor. Pretreatment of the precursor at low ratio of the phosphoric acid has added advantage, due to the tremendous increase in the apparent surface area of the resulting activated carbon and at the same time enriching its micropore nature. This could result in the conservation of the micropore fraction. On the other hand, using too high a ratio of the phosphoric acid to the precursor did not increase the apparent surface area very much, but instead destroyed the micropore component, and thus increasing the mesopore fraction of the resulting activated carbon. This study also shows that oil palm trunk, a by-product of oil palm industry has a great potential as a raw material for activated carbon production.