Yarub Al-Douri, Assoc. Prof. Dr.http://dspace.unimap.edu.my:80/xmlui/handle/123456789/391842024-03-28T23:21:23Z2024-03-28T23:21:23ZApplication of gold nanoparticles for electrochemical DNA biosensorAhmed Mishaal, MohammedRuslinda, Abdul Rahim, Dr.Ibraheem Jaleel, IbraheemFoo, Kai LoongHasrul Hisham, Che AhmadUda, Hashim, Prof. Dr.Yarub, Al-Douri, Assoc. Prof. Dr.http://dspace.unimap.edu.my:80/xmlui/handle/123456789/394402015-04-13T08:07:54Z2014-01-01T00:00:00ZApplication of gold nanoparticles for electrochemical DNA biosensor
Ahmed Mishaal, Mohammed; Ruslinda, Abdul Rahim, Dr.; Ibraheem Jaleel, Ibraheem; Foo, Kai Loong; Hasrul Hisham, Che Ahmad; Uda, Hashim, Prof. Dr.; Yarub, Al-Douri, Assoc. Prof. Dr.
An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl)triethoxysilane (APTES) as a linker molecule combined with the gold nanoparticles (GNPs) on thermally oxidized SiOthin films. The SiOthin films surface was chemically modified with a mixture of APTES and GNPs for DNA detection in different time periods of 30 min, 1 hour, 2 hours, and 4 hours, respectively. The DNA immobilization and hybridization were conducted by measuring the differences of the capacitance value within the frequency range of 1 Hz to 1 MHz. The capacitance values for DNA immobilization were 160 F, 77.8 F, 70 F, and 64.6 F, respectively, with the period of time from 30 min to 4 hours. Meanwhile the capacitance values for DNA hybridization were 44 F, 54 F, 55 F, and 61.5 F, respectively. The capacitance value of bare SiOthin film was 0.42 F, which was set as a base line for a reference in DNA detection. The differences of the capacitance value between the DNA immobilization and hybridization revealed that the modified SiOthin films using APTES and GNPs were successfully developed for DNA detection.
Link to publisher's homepage at http://www.hindawi.com/
2014-01-01T00:00:00ZStructural, elastic, electronic and optical properties of the newly synthesized monoclinic Zintl phase BaIn₂P₂Guechi, N.Abdelmadjid, BouhemadouS., Bin-OmranM., ChegaarYarub, Al-Douri, Assoc. Prof. Dr.Rabah, Khenata, Prof. Dr.A., Bourzamihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/355222014-06-15T13:34:26Z2014-03-01T00:00:00ZStructural, elastic, electronic and optical properties of the newly synthesized monoclinic Zintl phase BaIn₂P₂
Guechi, N.; Abdelmadjid, Bouhemadou; S., Bin-Omran; M., Chegaar; Yarub, Al-Douri, Assoc. Prof. Dr.; Rabah, Khenata, Prof. Dr.; A., Bourzami
The present study explores the structural, elastic, electronic and optical properties of the newly synthesized monoclinic Zintl phase BaIn₂P₂ using a pseudopotential plane-wave method in the framework of density functional theory within the generalized gradient approximation. The calculated lattice constants and internal coordinates are in very good agreement with the experimental findings. Independent single-crystal elastic constants as well as numerical estimations of the bulk modulus, the shear modulus, Young's modulus, Poisson's ratio, Pugh's indicator of brittle/ductile behaviour and the Debye temperature for the corresponding polycrystalline phase were obtained. The elastic anisotropy of BaIn₂P₂ was investigated using three different indexes. The calculated electronic band structure and the total and site-projected l-decomposed densities of states reveal that this compound is a direct narrow-band-gap semiconductor. Under the influence of hydrostatic pressure, the direct D–D band gap transforms into an indirect B-D band gap at 4.08 GPa, then into a B–Γ band gap at 10.56 GPa. Optical macroscopic constants, namely, the dielectric function, refractive index, extinction coefficient, reflectivity coefficient, absorption coefficient and energy-loss function, for polarized incident radiation along the [100], [010] and [001] directions were investigated.
Link to publisher's homepage at http://www.journals.elsevier.com
2014-03-01T00:00:00ZMorphology and optical investigations of ZnO pyramids and nanoflakes for optoelectronic applicationsN. K., HassanM. Roslan, HashimYarub, Al - Dourihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/350482014-06-04T03:51:36Z2014-06-01T00:00:00ZMorphology and optical investigations of ZnO pyramids and nanoflakes for optoelectronic applications
N. K., Hassan; M. Roslan, Hashim; Yarub, Al - Douri
Zinc-oxide (ZnO) pyramidal and nanoflakes were grown by electrochemical deposition of Zn(NO3)2·6H2O on n-type Si substrate with different crystallographic orientations and on indium tin oxide (ITO)-coated glass. Various morphological shapes of deposited ZnO nanostructures were observed, which were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bulk modulus was calculated to determine the material stiffness. Two peaks were observed at room temperature photoluminescence spectrum, i.e., a near-band-edge (NBE) emission in the UV region and a broad deep-level emission (DLE) in the green emission region. The optical properties were calculated to confirm the specific models validity of ZnO nanostructures for optoelectronics. The measured and calculated values show good agreement with other data.
Link to publisher's homepage at http://www.elsevier.com
2014-06-01T00:00:00Z