Uda Hashim
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Uda Hashim
Official Name
Uda, Hashim
Alternative Name
Hashimb, U.
Hashim, Uda
Hashim, U.
Uda, Hashim
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Scopus Author ID
22633937800
Researcher ID
CVC-6955-2022

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  • Publication
    Fabrication and characterizations of Al nanoparticles doped ZnO nanostructures-based integrated electrochemical biosensor
    ( 2020-01-01)
    Gherab K.
    ;
    AI-Douri Y.
    ;
    Uda Hashim
    ;
    Ameri M.
    ;
    Bouhemadou A.
    ;
    Batoo K.M.
    ;
    Adil S.F.
    ;
    Khan M.
    ;
    Raslan E.H.
    The benefits of the electrical-based biosensor include cheap production and fast response time of detecting diseases. An interdigitated electrode (IDE) is fabricated using silver (Ag) as a metal contact that is deposited on aliminium (Al) nanoparticles doped with both zinc oxide (ZnO) and Silicon (Si) forming AZO/Si nanostructures by vacuum coater in a thermal evaporator. The electrical properties are studied as a function of frequency and voltage using I-V characteristics. Sol-gel method under annealing temperature, 500 â—¦C is utilized to generate Al nanoparticles doped ZnO nanostructures. UV-vis spectrophotometer, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD) are used for analyzing optical, topographical, morphological and structural studies of AZO nanostructure, respectively. Specific empirical models of optical dielectric constant, bulk modulus and refractive index are also verified.
  • Publication
    Morphological, structural, and electrical characterization of sol-gel-synthesized ZnO nanorods
    ( 2013-02-03)
    M. Kashif
    ;
    Uda Hashim
    ;
    M. E. Ali
    ;
    Foo Kai Loong
    ;
    Syed M. Usman Ali
    ZnO nanorods were grown on thermally oxidized p-type silicon substrate using sol-gel method. The SEM image revealed high-density, well-aligned, and perpendicular ZnO nanorods on the oxidized silicon substrate. The XRD profile confirmed thec-axis orientation of the nanorods. PL measurements showed the synthesized ZnO nanorods have strong ultraviolet (UV) emission. The electrical characterization was performed using interdigitated silver electrodes to investigate the stability in the current flow of the fabricated device under different ultraviolet (UV) exposure times. It was notified that a stable current flow was observed after 60 min of UV exposure. The determination of stable current flow after UV exposure is necessary for UV-based gas sensing and optoelectronic devices.
      1  15
  • Publication
    Effective synthesis of silicon carbide nanotubes by microwave heating of blended silicon dioxide and multi-walled carbon nanotube
    ( 2017)
    Voo Chung Sung Tony
    ;
    Voon Chun Hong
    ;
    Lee Chang Chuan
    ;
    Lim Bee Ying
    ;
    Subash Chandra Bose Gopinath
    ;
    Foo Kai Loong
    ;
    Mohd Khairuddin Md Arshad
    ;
    Ruslinda A. Rahim
    ;
    Uda Hashim
    ;
    Nashaain Mohd Nordin
    ;
    Yarub Al-Douri
    Silicon carbide nanotube (SiCNTs) has been proven as a suitable material for wide applications in high power, elevated temperature and harsh environment. For the first time, we reported in this article an effective synthesis of SiCNTs by microwave heating of SiO2 and MWCNTs in molar ratio of 1:1, 1:3, 1:5 and 1:7. Blend of SiO2 and MWCNTs in the molar ratio of 1:3 was proven to be the most suitable for the high yield synthesis of β-SiCNTs as confirmed by X-ray diffraction pattern. Only SiCNTs were observed from the blend of MWCNTs and SiO2 in the molar ratio of 1:3 from field emission scanning electron microscopy imaging. High magnification transmission electron microscopy showed that tubular structure of MWCNT was preserved with the inter-planar spacing of 0.25 nm. Absorption bands of Si-C bond were detected at 803 cm-1 in Fourier transform infrared spectrum. Thermal gravimetric analysis revealed that SiCNTs from ratio of 1:3 showed the lowest weight loss. Thus, our synthetic process indicates high yield conversion of SiO2 and MWCNTs to SiCNTs was achieved for blend of SiO2 and MWCNTs in molar ratio of 1:3.
      4  32
  • Publication
    Impact of hydrogen concentrations on the impedance spectroscopic behavior of Pd-sensitized ZnO nanorods
    ( 2013-02-11)
    Muhammad Kashif
    ;
    Md Eaqub Ali
    ;
    Syed M Usman Ali
    ;
    Uda Hashim
    ;
    Sharifah Bee Abd Hamid
    ZnO nanorods were synthesized using a low-cost sol-gel spin coating technique. The synthesized nanorods were consisted of hexagonal phase having c-axis orientation. SEM images reflected perpendicular ZnO nanorods forming bridging network in some areas. The impact of different hydrogen concentrations on the Pd-sensitized ZnO nanorods was investigated using an impedance spectroscopy (IS). The grain boundary resistance (Rgb) significantly contributed to the sensing properties of hydrogen gas. The boundary resistance was decreased from 11.95 to 3.765 kΩ when the hydrogen concentration was increased from 40 to 360 ppm. IS gain curve showed a gain of 6.5 for 360 ppm of hydrogen at room temperature. Nyquist plot showed reduction in real part of impedance at low frequencies on exposure to different concentrations of hydrogen. Circuit equivalency was investigated by placing capacitors and resistors to identify the conduction mechanism according to complex impedance Nyquist plot. Variations in nanorod resistance and capacitance in response to the introduction of various concentrations of hydrogen gas were obtained from the alternating current impedance spectra.
      17  2
  • Publication
    A portable automatic endpoint detection system for amplicons of loop mediated isothermal amplification on microfluidic compact disk platform
    ( 2015)
    Shah Uddin
    ;
    Fatimah Ibrahim
    ;
    Abkar Sayad
    ;
    Aung Thiha
    ;
    Koh Pei
    ;
    Mas Mohktar
    ;
    Uda Hashim
    ;
    Jongman Cho
    ;
    Kwai Thong
    In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.
      4  42
  • Publication
    Integration of microfluidic channel on electrochemical-based nanobiosensors for monoplex and multiplex analyses: An overview
    ( 2023)
    Adam Hussaini
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Tijjani Adam
    ;
    Uda Hashim
    ;
    Zaliman Sauli
    ;
    Fakhri Makram A.
    ;
    Subramaniam Sreeramanan
    ;
    Chen Yeng
    ;
    Sasidharan Sreenivasan
    ;
    Wu Yuan Seng
    Background: Microfluidic devices have evolved into low-cost, simple, and powerful analytical tool platforms. Herein, an electrochemically-based microfluidic nanobiosensor array for monoplex and multiplex detection of physiologically relevant analytes is reviewed. Unlike other analyte detection methods, microfluidics-based embedded electrochemical nanobiosensors are portable, custom electrochemical readers for signal reading. Methods: Microfluidic devices and electrochemical sensors can be integrated into monoplex or multiplex systems. The integrated system is simple to use and sensitive, and so has great potential as a powerful tool for profiling immune-mediated treatment responses in real time. It may also be developed further as a point-of-care diagnostic device for conducting near-patient tests using biological samples. Therefore, using mutiplex analysis, a biosensor array may detect multiple analytes in a sample solution and provide different outputs for each analyte. A microfluidic electrochemical nanobiosensor, for example, can detect urine glucose, lactate, and uric acid. The microfluidic array of integrated nanobiosensors and electrochemical sensors enables fast and cost-effective selection of high-quality and statistically significant diagnostic data at the point of care. The multiplex analytical test is an important molecular tool for academic research as well as clinical diagnosis. Although key approaches for analysing numerous analytes have been developed, none of them are suitable for point-of-care diagnostics, especially in situations with limited resources. Significant findings: In this study, monoplex and multiplex microfluidic assays for rapid measurement of single and multiple analytes at the point of care are presented. Since this test can analyse both single and multiple analytes, it is exceptionally specific, easy to use, and inexpensive. The ability of integrated electrochemical-based microfluidic devices with single channel and multiple channels systems to perform monoplex and multiplex analysis simultaneously and independently is the novelty of this review.
      2