Now showing 1 - 6 of 6
  • Publication
    Preliminary studies on antimicrobial activity of extracts from aloe vera leaf, citrus hystrix leaf, zingiber officinale and Sabah snake grass against bacillus subtilis
    Herbal plants have several potential antimicrobial activities either as antifungal or antibacterial to fight against the disease and pathogen that attack the plants. The extractions of the Aloe vera leaf, Citrus hystrix leaf, Zingiber officinale rhizome and Sabah snake grass were selected in this study to fight against Bacillus subtilis. B. subtilis is a Gram-positive bacterium, rodshaped and catalase-positive that lives on decayed organic material. It is known as Gram-positive bacteria because of its thick peptidoglycan and would appear purple when subjected to Gram test. This species is commonly found in the upper layers of the soil, in meat or vegetables, in pastry, cooked meat, in bread or poultry products. The extracts of Sabah Snake Grass found to be most effective than A.vera leaf, Z. officinale, and C. hystrix against the B. subtilis.
  • Publication
    Hydrothermal growth of titania nanowires for SAW device sensing area
    Synthesis of titania or titanium dioxide (TiO 2) is attracted to energy and environmental applications. Here, the growth of nanostructure TiO 2 nanowires on Si (100) substrates by using the two-step method. Different seed layers of TiO 2 were deposited by spin coating and annealing, followed by the growth of TiO 2 nanowires by using the hydrothermal method. The sol-gel technique was used in preparing the TiO 2 solution for the thin film deposition purpose. Acetic acid, hydrochloric acid and tris (2-aminoethyl) amine were used as a stabilizer to synthesize three different TiO 2 seed layers. The aim of this study was to understand the role of polycrystalline size on thin film towards the diameter of nanowires grown as a sensing area in Surface Acoustic Wave (SAW) Biosensor. The morphology and structure of the thin film and TiO 2 nanowires were characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM).
  • Publication
    Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device
    In fabricating Surface Acoustic Wave (SAW) biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO) with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam) and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM) for surface morphology and X-ray Diffraction (XRD) for phase structure.
  • Publication
    Enhancement of Lithium Niobate nanophotonic structures via spin-coating technique for optical waveguides application
    ( 2017)
    Makram A. Fakhri
    ;
    M.Halim A. Wahid
    ;
    Ban A. Badr
    ;
    Suad M. Kadhim
    ;
    Evan T. Salim
    ;
    ;
    Zaid T. Salim
    This work is dedicated to investigation of temperature effects in Lithium Niobate (LiNbO3) nanostructures. The LiNbO3 nanostructures were deposited on glass substrate by spin-coating technique. LiNbO3 was set down at 3000 rpm for 30 sec and annealed from 100 to 600 o C. The structures were characterized and analyzed by scanning electron microscopy (SEM) and ultra-violet visible (UV-vis) spectrophotometer. The measured results have showed that by increasing annealing temperatures, the structures start to be more crystallized and be more homogenized until the optimum arrangement was achieved. Once this was accomplished, it’s applicable for optical waveguides development. Eventually, it starts to be less crystallization and non-homogeneous. Energy gap was recorded to be at average value of 3.9 eV.
  • Publication
    The structure and optical properties of Lithium Niobate grown on quartz for photonics application
    ( 2017)
    Makram A. Fakhri
    ;
    ;
    Suad M. Kadhim
    ;
    Ban A. Badr
    ;
    Evan T. Salim
    ;
    ;
    Zaid T. Salim
    This paper focuses on the structure and optical properties of Lithium niobate (LN) deposited on quartz substrate by sol-gel method. The solution was prepared at different molarity concentration and annealed at 500 °C. The LNs were analyzed by UV-visible, X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results show that as the molar concentration increases, the films crystallization becomes more atomically distributed and the energy band gap approaches 4 eV. Transmission spectra were taken in the wavelength range of 400-1100 nm. Hexagonal structure was observed with good atoms distribution and homogeneous crystallization. There were two phases of LNs recorded in this work.
  • Publication
    FET-biosensor for cardiac troponin biomarker
    Acute myocardial infarction or myocardial infarction (MI) is a major health problem, due to diminished flow of blood to the heart, leads to higher rates of mortality and morbidity. The most specific markers for cardiac injury are cardiac troponin I (cTnI) and cardiac troponin T (cTnT) which have been considered as ‘gold standard’. Due to higher specificity, determination of the level of cardiac troponins became a predominant indicator for MI. Currently, field-effect transistor (FET)-based biosensors have been main interest to be implemented in portable sensors with the ultimate application in point-of-care testing (POCT). In this paper, we review on the FET-based biosensor based on its principle of operation, integration with nanomaterial, surface functionalization as well as immobilization, and the introduction of additional gate (for ambipolar conduction) on the device architecture for the detection of cardiac troponin I (cTnI) biomarker.