Now showing 1 - 10 of 54
  • Publication
    Arthropods-mediated green synthesis of Zinc oxide nanoparticles using cellar spider extract a biocompatible remediation for environmental approach
    ( 2024-06) ; ;
    M. A. R. Irfan
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    ; ; ;
    MRM Huzaifah
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    Maimunah Mohd Ali
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    Nur Hulwani Ibrahim
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    Muaz Mohd Zaini Makhtar
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    ; ; ; ; ;
    Mahfuz Affif Mohd Ruslan
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    This study presents an eco-friendly approach to synthesizing zinc oxide nanoparticles (ZnO NPs) using extracts from cellar spiders, addressing environmental and health concerns associated with conventional methods. The spider extract efficiently reduced zinc acetate dihydrate, and the synthesized ZnO NPs underwent comprehensive quantitative characterization, including size, shape, morphology, surface chemistry, thermal stability, and optical properties using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential measurements, thermogravimetric analysis (TGA), and UV-vis spectroscopy. The nanoparticles exhibited intended characteristics, and their adsorption capability for methylene blue (MB) was quantitatively assessed using the Freundlich isotherm model and pseudo-second-order kinetic model, providing numerical insights into MB removal efficiency. The study demonstrates the potential of these green-synthesized ZnO NPs for applications in environmental remediation, wastewater treatment, and antibacterial therapies, contributing to both sustainable nanomaterial development and quantitative understanding of their functional properties.
  • Publication
    The study of sensing elements parameters optimization for developed biosensor of SARS-CoV-2 detection
    ( 2023-04)
    Fatin Syakirah Halim
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    ; ; ; ;
    Iffah Izzati Zakaria
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    Wei Chern Ang
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    Nurfareezah Nadhirah Jaapar
    New advancements in developing sensitive and selective biosensors have demonstrated outstanding potential for Deoxyribonucleic Acid (DNA biosensors). The detection mode of DNA biosensors primary depends on a particular DNA hybridization that precisely occurs on the surface of the physical transducer that can only be detected using high-performance assays due to slight current changes. The analytical performance (sensitivity) of the DNA biosensor is conclusively rely on the confluence constructing of the sensing surface, which must be optimized. Thus, in this study, the sensing elements of the developed biosensors were optimized for detecting RNA of SARS-CoV-2. This optimization included concentration of nanomaterials (carbon quantum dots), probe density (concentration of DNA probe) and concentration of linker (APTES). It was observed that 0.15 % V/V of concentration CQD, 0.1μM of DNA probe and 36% V/V of APTES were the optimum parameters which provided their maximum response during electrical measurements and increased the sensitivity of the developed biosensor for SARS-CoV-2 detection
  • Publication
    Potentials of MicroRNA in Early Detection of Ovarian Cancer by Analytical Electrical Biosensors
    ( 2022-01-01) ; ; ;
    Nadzirah S.
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    Salimi M.N.
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    ; ;
    Muhammad Nur Afnan Uda
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    Rozi S.K.M.
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    Rejali Z.
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    Afzan A.
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    Azan M.I.A.
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    Yaakub A.R.W.
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    Hamzah A.A.
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    Dee C.F.
    The importance of nanotechnology in medical applications especially with biomedical sensing devices is undoubted. Several medical diagnostics have been developed by taking the advantage of nanomaterials, especially with electrical biosensors. Biosensors have been predominantly used for the quantification of different clinical biomarkers toward detection, screening, and follow-up the treatment. At present, ovarian cancer is one of the severe complications that cannot be identified until it becomes most dangerous as the advanced stage. Based on the American Cancer Society, 20% of cases involved in the detection of ovarian cancer are diagnosed at an early stage and 80% diagnosed at the later stages. The patient just has a common digestive problem and stomach ache as early symptoms and people used to ignore these symptoms. Micro ribonucleic acid (miRNA) is classified as small non-coding RNAs, their expressions change due to the association of cancer development and progression. This article reviews and discusses on the currently available strategies for the early detection of ovarian cancers using miRNA as a biomarker associated with electrical biosensors. A unique miRNA-based biomarker detections are specially highlighted with biosensor platforms to diagnose ovarian cancer.
  • Publication
    Production and characterization of graphene from carbonaceous rice straw by cost-effect extraction
    ( 2021-05-01) ; ; ;
    Halim N.H.
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    Muhammad Nur Afnan Uda
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    Anbu P.
    This paper describes the synthesis of graphene-based activated carbon from carbonaceous rice straw fly ash in an electrical furnace and the subsequent potassium hydroxide extraction. The produced graphene has a proper morphological structure; flakes and a rough surface can be observed. The average size of the graphene was defined as up to 2000 nm and clarification was provided by high-resolution microscopes (FESEM and FETEM). Crystallinity was confirmed by surface area electron diffraction. The chemical bonding from the graphene was clearly observed, with –C=C– and O–H stretching at peaks of 1644 cm−1 and 3435 cm−1, respectively. Impurities in the graphene were found using X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The measured size, according to zeta-potential analysis, was 8722.2 ± 25 nm, and the average polydispersity index was 0.576. The stability of the mass reduction was analyzed by a thermogravimetric at 100 Â°C, with a final reduction of ~ 11%.
  • Publication
    Microwave welding of thermoplastic using silicon carbide nanowhiskers as susceptor effect of heating duration
    ( 2024-06)
    Phey Yee Foong
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    ; ; ; ; ; ; ;
    Foo Wah Low
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    Muhammad Kashif
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    Nor Azura Abdul Rahman
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    Veeradasan Perumal
    Microwave welding is becoming more popular than conventional joining methods due to its advantages such as rapid and localised heating as well as applicable to components with complicated geometry. Previously reported susceptor, such as carbonaceous materials and conductive polymers, are toxic and the welding process involving these susceptors is time-consuming. Because of its exceptional microwave absorption and biocompatibility, silicon carbide nanowhiskers (SiCNWs) was employed as the microwave susceptor for microwave welding. Microwave welding in this study comprises of only three simple steps: SiCNWs suspension preparation, SiCNWs application and microwave heating. The weld strength of welded joint was then characterised using tensile test and energy dispersive x-ray spectroscopy equipped scanning electron microscopy (EDS-SEM) to study its mechanical properties and cross-section microstructure. The influence of microwave irradiation time was studied in this study, and it is found that the weld strength rose with the extension of microwave irradiation time, until a maximum weld strength of 1.61 MPa was achieved by 17 s welded joint. The development of SiCNWs reinforced PP nanocomposite welded joint layer is responsible for the enhanced weld strength. Prolonged heating duration may also result in flaws such as void formation at the welded joint, which subsequently lowered the weld strength to 0.60 MPa when the heating duration was extended to 20 s. In sum, a strengthen welded joint can be formed with rapid microwave heating under the proper control of heating duration.
  • Publication
    Morphological Analysis of Fabricated 5.0 μM Interdigitated Electrode (IDE)
    ( 2021-12-14) ; ; ;
    Muhammad Nur Afnan Uda
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    Halim N.H.
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    Hashim M.K.R.
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    Anbu P.
    The aim of this research is to study the morphological analysis of fabricated Interdigitated Electrode (IDE). This device electrode was physically characterized using 3D nano profiler, scanning electrode microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Atomic Force Microscope (AFM). Based on this analysis, IDE pattern was analyzed thoroughly based on the IDE pattern specifications with 5 μM finger gap and this research significantly will stand as a platform quantify the biomolecules in further analysis.
  • Publication
    Analysis on silica and graphene nanomaterials obtained from rice straw for antimicrobial potential
    This study focuses on the encapsulation of silica and graphene nanoparticles and their potential applications. The encapsulation enhances the properties and effectiveness of these nanoparticles, with silica providing stability and graphene contributing to high surface area and electrical conductivity. Characterization of silica-graphene nanoparticles was conducted using various techniques including High Power Microscope (HPM), Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), and 3D Nano Profiler. The antimicrobial activity of silica, graphene, and silica-graphene nanoparticles was evaluated using a disc diffusion assay against E. coli and B. subtilis at varying concentrations. Results showed significant antimicrobial activity, with the inhibition zone being directly proportional to the concentration. Silica-graphene nanoparticles demonstrated higher efficacy against E. coli compared to B. subtilis, attributed to differences in cell wall structure. Statistical analysis using ANOVA confirmed significant differences in antimicrobial activity among the tested components.
  • Publication
    Novelty Studies on Amorphous Silica Nanoparticle Production from Rice Straw Ash
    ( 2020-07-09) ; ; ;
    Muhammad Nur Afnan Uda
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    Halim N.H.
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    Anbu P.
    Turning waste product into the valuable resources is the best alternative way to overcome the waste management issue. Generally, rice is grown and planted twice a year where a lot of rice by-products have been produced after harvesting the matured paddy. Rice straw is one of turning waste products into the valuable resources and to manage the environmental issues. Generally, rice is grown and planted twice a year where a lot of rice by-products are produced. Rices straw is one of the rice by-products, generated roughly 0.7-1.4 kg per kilograms of harvested milled rice. With the nanotechnological approach, silica particles at nano-size can be produced using the incinerated rice straw. In addition to that, this research will report the synthesis, characterization and adsorption analysis towards the heavy metal removal.
  • Publication
    New Development Quantification Methods for Salt Iodine and Urinary Iodine Using Microfluidics Based Nanotechnology
    ( 2020-03-18)
    Nur Hulwani Ibrahim
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    ; ; ; ;
    Muhammad Nur Afnan Uda
    In Malaysia, the first Iodine Deficiency Disorders (IDD) survey was conducted in 1996 and it was discovered that Peninsular Malaysia did not have IDD problem until latter studies showed goitre occurrence of 34.7% in Hulu Langat district and urinary iodine lower than the adequate level of (100-199 ug/L) in Perak and Pahang states (Selamat et al., 2010). Baseline and periodical sampling of children and pregnant woman urine and imported salt commodities for the consumption of the population is mandatory for iodine measurement. Thus, development of quantitative methods of measurement of salt and food iodine is crucial for implementation of the USI program nationwide. In this study, interdigitated electrode (IDE) biosensor, a rapid, sensitive and selective method has been developed to determine the iodine content in both urine and salt. This method includes functionalization and silanization step using 3-aminopropyl triethoxysilane (APTES). The I-V characterization of IDE biosensor was performed using (Keithley 2450), Kickstart software and Probestation. It measures the amount of current flow through IDE which is directly proportional to the concentration of iodine in both urine and salt. Hence, IDE biosensor is proven to be a rapid, selective, sensitive method and can be developed as a new nanotechnology for the elimination of Iodine Deficiency Disorders (IDD) among children and pregnant woman.
  • Publication
    Titanium dioxide–mediated resistive nanobiosensor for E. coli O157:H7
    ( 2020-04-01)
    Nadzirah S.
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    Hamzah A.A.
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    Yu H.W.
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    Dee C.F.
    A titanium dioxide nanoparticle (TiO2 NP)–mediated resistive biosensor is described for the determination of DNA fragments of Escherichia coli O157:H7 (E. coli O157:H7). The sol-gel method was used to synthesize the TiO2 NP, and microlithography was applied to fabricate the interdigitated sensor electrodes. Conventional E. coli DNA detections are facing difficulties in long-preparation-and-detection-time (more than 3 days). Hence, electronic biosensor was introduced by measuring the current-voltage (I–V) DNA probe without amplification of DNA fragments. The detection scheme is based on the interaction between the electron flow on the sensor and the introduction of negative charges from DNA probe and target DNA. The biosensor has a sensitivity of 1.67 × 1013 Î©/M and a wide analytical range. The limit detection is down to 1 × 10−11 M of DNA. The sensor possesses outstanding repeatability and reproducibility and is cabable to detect DNA within 15 min in a minute-volume sample (1 Î¼L). [Figure not available: see fulltext.].