Uda Hashim
Thumbnail Image
Preferred name
Uda Hashim
Official Name
Uda, Hashim
Alternative Name
Hashimb, U.
Hashim, Uda
Hashim, U.
Uda, Hashim
Main Affiliation
Scopus Author ID
22633937800
Researcher ID
CVC-6955-2022

Research Output

Filters

1 1
180
Reset filters

Settings
Now showing 1 - 10 of 180
No Thumbnail Available
Publication

Synthesis of Titanium-Dioxide using pulsed laser deposition at various pulsed laser energies

2022-12 , Rami S. Mohammed , Makram A. Fakhri , Forat H. Alsultany , Uda Hashim

Titanium dioxide (TiOâ‚‚) is a widely available transparent conducting oxide (TCO). In recent years it attracted the attention of researchers due to its compatibility with several applications. To achieve the best TiOâ‚‚ thin film properties possible, the deposition parameters must be optimized. In this research, TiOâ‚‚ was deposited on silicon and quarts by pulsed laser deposition (PLD) technique aiming to study the effect of changing the energy of the PLD Nd-YAG laser between 500, 600, and 700mJ. The optical properties have been investigated using a UV-Vis spectrophotometer, morphological properties using Atomic Force Microscopy, and structural properties using an X-ray diffractometer and Raman spectrometer. 700mJ was proven to provide the best thin film properties, the tests and measurements have shown a crystalline structure, and the distribution of the grains was regularly in the film. Raman spectroscopy showed two diffraction peaks corresponding to anatase Eg and rutile Eg. This observation is typically used in dye-sensitized solar cells, separation sensor devices, and more.

View
No Thumbnail Available
Publication

Titanium dioxide nanoparticle-based interdigitated electrodes: A novel current to voltage DNA biosensor recognizes E. coli O157:H7

2015 , Sh. Nadzirah , N. Azizah , Uda Hashim , Subash Chandra Bose Gopinath , Mohd Kashif

Nanoparticle-mediated bio-sensing promoted the development of novel sensors in the front of medical diagnosis. In the present study, we have generated and examined the potential of titanium dioxide (TiO 2) crystalline nanoparticles with aluminium interdigitated electrode biosensor to specifically detect single-stranded E.coli O157:H7 DNA. The performance of this novel DNA biosensor was measured the electrical current response using a picoam-meter. The sensor surface was chemically functionalized with (3-aminopropyl) triethoxysi-lane (APTES) to provide contact between the organic and inorganic surfaces of a single-stranded DNA probe and TiO 2 nanoparticles while maintaining the sensing system’s physi-cal characteristics. The complement of the target DNA of E. coli O157:H7 to the carboxyl-ate-probe DNA could be translated into electrical signals and confirmed by the increased conductivity in the current-to-voltage curves. The specificity experiments indicate that the biosensor can discriminate between the complementary sequences from the base-mis-matched and the non-complementary sequences. After duplex formation, the complemen-tary target sequence can be quantified over a wide range with a detection limit of 1.0 x 10 -13 M. With target DNA from the lysed E. coli O157:H7, we could attain similar sensitivity. Sta-bility of DNA immobilized surface was calculated with the relative standard deviation (4.6%), displayed the retaining with 99% of its original response current until 6 months. This high-performance interdigitated DNA biosensor with high sensitivity, stability and non-foul-ing on a novel sensing platform is suitable for a wide range of biomolecular interactive analyses.

View
No Thumbnail Available
Publication

Nanobioprobe for the determination of pork adulteration in burger formulations

2012-02-14 , Mohamad Eaqub Ali , S. Mustafa , Uda Hashim , Y. B. Che Man , K. L. Foo

We report the development of a swine-specific hybrid nanobioprobe through a covalent integration of a fluorophore-labeled 27-nucleotideAluI-fragment of swine cytochrome b gene to a 3 nm gold nanoparticle for the determination of pork adulteration in processed meat products. We tested the probe to estimate adulterated pork in ready-to-eat pork-spiked beef burgers. The probe quantitatively detected 1–100% spiked pork in burger formulations with ≥90% accuracy. A plot of observed fluorescence against the known concentration ofAluI-digested pork DNA targets generated a concave curve, demonstrating a power relationship (y=2.956x0.509) with a regression coefficient (R2) of 0.986. No cross-species detection was found in a standard set of pork, beef, chicken, mutton, and chevon burgers. The method is suitable for the determination of very short-length nucleic acid targets which cannot be estimated by conventional and real-time PCR but are essential for the determination of microRNA in biodiagnostics and degraded DNA in forensic testing and food analysis.

View
No Thumbnail Available
Publication

Low temperature annealed zinc oxide nanostructured thin film-based transducers: Characterization for sensing applications

2015 , R. Haarindraprasad , Uda Hashim , Subash Chandra Bose Gopinath , Muhammad Kashif , P. Veeradasan , S. R. Balakrishnan , Foo Kai Loong , Prabakaran A/L Poopalan

The performance of sensing surfaces highly relies on nanostructures to enhance their sensitivity and specificity. Herein, nanostructured zinc oxide (ZnO) thin films of various thicknesses were coated on glass and p-type silicon substrates using a sol-gel spin-coating technique. The deposited films were characterized for morphological, structural, and optoelectronic properties by high-resolution measurements. X-ray diffraction analyses revealed that the deposited films have a c-axis orientation and display peaks that refer to ZnO, which exhibits a hexagonal structure with a preferable plane orientation (002). The thicknesses of ZnO thin films prepared using 1, 3, 5, and 7 cycles were measured to be 40, 60, 100, and 200 nm, respectively. The increment in grain size of the thin film from 21 to 52 nm was noticed, when its thickness was increased from 40 to 200 nm, whereas the band gap value decreased from 3.282 to 3.268 eV. Band gap value of ZnO thin film with thickness of 200 nm at pH ranging from 2 to 10 reduces from 3.263eV to 3.200 eV. Furthermore, to evaluate the transducing capacity of the ZnO nanostructure, the refractive index, optoelectric constant, and bulk modulus were analyzed and correlated. The highest thickness (200 nm) of ZnO film, embedded with an interdigitated electrode that behaves as a pH-sensing electrode, could sense pH variations in the range of 2-10. It showed a highly sensitive response of 444 μAmM-1cm-2 with a linear regression of R2 =0.9304. The measured sensitivity of the developed device for pH per unit is 3.72μA/pH.

View
No Thumbnail Available
Publication

Preliminary studies on antimicrobial activity of extracts from aloe vera leaf, citrus hystrix leaf, zingiber officinale and Sabah snake grass against bacillus subtilis

2018 , Muhammad Nur Aiman Uda , Subash Chandra Bose Gopinath , Nur Hulwani Ibrahim , Mohd Khairul Rabani Hashim , Nuradibah Mohd Amer , Midhat Nabil Ahmad Salimi , Tan Ewe Shen , Ong Yee Fen , Maisara Azad Mat Akhir , Uda Hashim

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.

View
No Thumbnail Available
Publication

Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device

2017 , Mohd Rosydi Zakaria , Shazlina Johari , Mohd Hafiz Ismail , Uda Hashim

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.

View
No Thumbnail Available
Publication

Effect of hydrochloric acid concentration on morphology of polyaniline nanofibers synthesized by rapid mixing polymerization

2015 , Zulkhairi Zakaria , Nurul F. A. Halim , Mubaraq H. V. Schleusingen , A. K. M. Shafiqul Islam , Uda Hashim , Mohd N. Ahmad

Polyaniline (PANI) nanofibers with diameters ranging from 60 nm to 190 nm were successfully synthesized by rapid mixing polymerization method at room temperature. The effects of synthesis conditions such as concentration of hydrochloric acid (HCl), ammonium persulfate (APS), and aniline monomer (Ani) on the morphology of PANI nanofibers were investigated using scanning electron microscopy (SEM). FTIR and UV-Vis analysis were performed to characterize the PANI nanofibers. The effect of polymerization time and electrical properties of PANI nanofibers was also discussed. A rapid mixing polymerization method is found to be advantageous in producing bulk quantities of nanofibers.

View
No Thumbnail Available
Publication

Silica and graphene mediate arsenic detection in mature rice grain by a newly patterned current–volt aptasensor

2021 , M. N. A. Uda , Subash Chandra Bose Gopinath , Uda Hashim , N. H. Halim , N. A. Parmin , M. N. Afnan Uda , Tijjani Adam , Periasamy Anbu

Arsenic is a major global threat to the ecosystem. Here we describe a highly accurate sensing platform using silica nanoparticles/graphene at the surface of aluminum interdigitated electrodes (Al IDE), able to detect trace amounts of arsenic(III) in rice grain samples. The morphology and electrical properties of fabricated Al IDEs were characterized and standardized using AFM, and SEM with EDX analyses. Micrometer scale Al IDEs were fabricated with silicon, aluminum, and oxygen as primary elements. Validation of the bare Al IDE with electrolyte fouling was performed at different pH levels. The sensing surface was stable with no electrolyte fouling at pH 7. Each chemical modification step was monitored with current–volt measurement. The surface chemical bonds were characterized by fourier transform infrared spectroscopy (FTIR) and revealed different peaks when interacting with arsenic (1600–1000 cm−1). Both silica nanoparticles and graphene presented a sensitive limit of detection as measured by slope calibration curves at 0.0000001 pg/ml, respectively. Further, linear regression was established using ΔI (A) = 3.86 E−09 log (Arsenic concentration) [g/ml] + 8.67 E−08 [A] for silica nanoparticles, whereas for graphene Y = 3.73 E−09 (Arsenic concentration) [g/ml] + 8.52 E−08 on the linear range of 0.0000001 pg/ml to 0.01 pg/ml. The R2 for silica (0.96) and that of graphene (0.94) was close to the maximum (1). Modification with silica nanoparticles was highly stable. The potential use of silica nanoparticles in the detection of arsenic in rice grain extract can be attributed to their size and stability.

View
No Thumbnail Available
Publication

Modular architecture of a non-contact pinch actuation micropump

2012 , Pei Song Chee , Rashidah Arsat , Tijjani Adam , Uda Hashim , Ruzairi Abdul Rahim , Pei Ling Leow

This paper demonstrates a modular architecture of a non-contact actuation micropump setup. Rapid hot embossing prototyping was employed in micropump fabrication by using printed circuit board (PCB) as a mold material in polymer casting. Actuator-membrane gap separation was studied, with experimental investigation of three separation distances: 2.0 mm, 2.5 mm and 3.5 mm. To enhance the micropump performance, interaction surface area between plunger and membrane was modeled via finite element analysis (FEA). The micropump was evaluated against two frequency ranges, which comprised a low driving frequency range (0–5 Hz, with 0.5 Hz step increments) and a nominal frequency range (0–80 Hz, with 10 Hz per step increments). The low range frequency features a linear relationship of flow rate with the operating frequency function, while two magnitude peaks were captured in the flow rate and back pressure characteristic in the nominal frequency range. Repeatability and reliability tests conducted suggest the pump performed at a maximum flow rate of 5.78 mL/min at 65 Hz and a backpressure of 1.35 kPa at 60 Hz.

View
No Thumbnail Available
Publication

Fabrication of silicon nitride ion sensitive field-effect transistor for pH measurement and DNA Immobilization/Hybridization

2013 , Uda Hashim , Soon Weng Chong , Liu Wei Wen

The fabrication of ion sensitive field-effect transistor (ISFET) using silicon nitride (Si3N4) as the sensing membrane for pH measurement and DNA is reported. For the pH measurement, the Ag/AgCl electrode was used as the reference electrode, and different pH values of buffer solution were used in the ISFET analysis. The ISFET device was tested with pH buffer solutions of pH2, pH3, pH7, pH8, and pH9. The results show that the IV characteristic of ISFET devices is directly proportional and the device’s sensitivity was 43.13 mV/pH. The ISFET is modified chemically to allow the integration with biological element to form a biologically active field-effect transistor (BIOFET). It was found that the DNA immobilization activities which occurred on the sensing membrane caused the drain current to drop due to the negatively charged backbones of the DNA probes repelled electrons from accumulating at the conducting channel. The drain current was further decreased when the DNA hybridization took place.

View