Journal Articles

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https://hdl.handle.net/20.500.14170/1977

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Browsing Journal Articles by Department "Faculty of Electronic Engineering & Technology"
  • Publication
    Binding dynamics and conformational stability of graphene-based nanomaterials with Mutant LOX-1: Insights from molecular docking and dynamics simulations in atherosclerosis
    (Springer, 2024-12)
    Farizah Hanim Lat
    ;
    Ahmad Naqib Shuid
    ;
    Mohd Yusmaidie Aziz
    ;
    Muhammad Mahyiddin Ramli
    ;
    Rafeezul Mohamed
    Oxidized low-density lipoprotein (oxLDL) is a critical factor in endothelial dysfunction and serves as an important biomarker for oxidative stress. Recent research has focused on lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), a receptor for oxLDL that plays a significant role in atherosclerosis progression. Mutant LOX-1 may show changes in its binding affinity for oxLDL, potentially leading to variations in oxLDL uptake and foam cell formation. Our previous investigation into graphene-based nanomaterials and their interactions with atherosclerosis-related proteins, including LOX-1, provided important insights into their binding characteristics. In this study, we delve deeper into the binding dynamics between graphene-based nanomaterials and mutant LOX-1, aiming to clarify their implications for atherosclerotic development. Using molecular docking techniques with AutodockVina and active site predictions from P2Rank, we evaluated the binding affinities of graphene, graphene oxide (GO), and reduced graphene oxide (rGO) to mutant LOX-1. Notably, all docking scores were below -5 kcal/mol, indicating strong interactions with the receptor. To investigate the dynamics of these interactions further, we performed molecular dynamics (MD) simulations using the CHARMM force field. Our simulations revealed significant conformational changes within the first 100 ns, particularly in the mutant LOX-1 and GO complex, which suggested improved binding stability. These results enhance our understanding of how graphene-based nanomaterials interact with mutant forms of LOX-1, offering potential avenues for targeted therapies in atherosclerosis management related to LOX-1 dysregulation.
  • Publication
    Physical, mechanical and electrical properties of Chitosan/Graphene Oxide composite films for Copper Ions (Cu²+) detection
    (Springer, 2023)
    Mohammad Abdull Halim Mohd Abdull Majid
    ;
    Nurul Huda Osman
    ;
    Nizam Tamchek
    ;
    Nurul Asyikin Ahmad Sukri
    ;
    Hazeem Ikhwan Mazlan
    ;
    Nurul Najiha Mazu
    ;
    Adilah Idris
    ;
    Josephine Ying Chyi Liew
    ;
    Muhammad Mahyiddin Ramli
    Copper ions are one of the metal ions that contribute significantly to water pollution and threaten the ecosystem. The threat heightened the importance of the detection and removal of the contaminants. In this study, the Chitosan/Graphene Oxide (CH/GO) composite film was synthesized at different GO ratios via a direct casting technique. The structural, mechanical and film adsorption capacities were characterized along with the electrical properties. The results revealed that adding GO into CH at a 1:5 ratio produces the highest strength and adsorption capacity. The 1:5 film was then tested for its electrical properties to see the possibility of utilizing it as part of an electrical measurement system. Various electrical parameters such as permittivity (ε′, ε″), Tanδ, bulk resistivity (Rb) and DC conductivity (σDC) were studied. Results show that the 1:5 ratio chitosan film in various Cu²+ concentrations yielded significant differences in electrical properties. The Rb and σDC gave the most significant results and can be used as Cu²+ detection parameters.
      3  23
  • Publication
    Revolutionizing cancer treatment by boosting dendritic cell vaccine efficacy with graphene oxide
    (EnPress Publisher LLC, 2023)
    Rafeezul Mohamed
    ;
    Muhammad Mahyiddin Ramli
    ;
    Ali H Reshak
    ;
    Nurul Huda Osman
    ;
    Mohd Yusmaidie Aziz
    ;
    Mohd Syahir Mansor
    Dendritic cells (DCs) are potent antigen presenting cells that play a crucial role in stimulating T cell responses against cancer. DC vaccines have been utilized as an immunotherapy approach for cancer treatment, but their effectiveness is hampered by challenges in the tumor microenvironment. Graphene oxide (GO), a cutting-edge carbon-based nanomaterial, has shown promise in modulating DC activation and function. This review highlights the recent advancements in DC vaccines and explores how GO can enhance their efficacy for cancer treatment. By leveraging the unique properties of GO, such as its biocompatibility and immunomodulatory effects, DC vaccines can potentially be optimized to overcome the limitations of the tumor microenvironment and achieve improved outcomes in cancer immunotherapy.
      3  6
  • Publication
    Semiconducting biomass-based amorphous carbon films and their potential application in photovoltaic devices
    (Elsevier Ltd, 2025)
    Endhah Purwandari
    ;
    Retno Asih
    ;
    Sudarsono
    ;
    Diky Anggoro
    ;
    Gerald Ensang Timuda
    ;
    Malik Anjelh Baqiya
    ;
    Iman Santoso
    ;
    Hideki Nakajima
    ;
    Muhammad Mahyiddin Ramli
    ;
    Agus Subekti
    ;
    Darminto
    Amorphous carbon (aC) is highly appealing because of its unique structure, electrical and optical properties, making it appropriate for various applications, especially in energy conversion. This work presents a comprehensive study on the synthesis of aC materials, including both intrinsic (i-type) and doped conditions (p- and n-type), to enhance the performance of photovoltaic films. Carbon materials are derived from biomass using a straightforward and environmentally conscious technique. The obtained carbon compound demonstrates an amorphous state with a substantial prevalence of the sp2 C=C component. Raman spectroscopy and electron microscopy confirmed the stacking of 2D layers forming a multilayer graphene structure. The carbon compound prepared AC films deposited onto a quartz glass surface via spray coating. The films have a thickness ranging from 247 to 478 nm. The dielectric constants of the optical parameters reveal resonant exciton features at a photon energy of ∼3.8 eV, whereas the real component exhibits semiconductive properties. The refractive indices of the p-, i-, and n-layers, which have gap energies in decreasing order, demonstrate a decline. The optical conductivity of aC is higher than that of amorphous silicon, specifically 0.54 × 103Ω−1cm−1, 0.48 × 103 Ω−1cm−1, and 0.53 × 103 Ω−1cm−1 for the p-, i-, and n-type films, respectively. Based on this outcome, it is reasonable to suggest that the recently developed material is potentially important as a photovoltaic device.