Ahmad Radi Wan Yaakub
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Ahmad Radi Wan Yaakub
Official Name
Ahmad Radi, Wan Yaakub
Alternative Name
Wan Yaakub, Ahmad Radi
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Scopus Author ID
57221283601

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  • Publication
    Analysis on silica and graphene nanomaterials obtained from rice straw for antimicrobial potential
    ( 2024-06)
    Muhammad Nur Aiman Uda
    ;
    N. H. A Jalil
    ;
    Muhammad Firdaus Abdul Muttalib
    ;
    Fahisal Abdullah
    ;
    Uda Hashim
    ;
    Subash Chandra Bose Gopinath
    ;
    Shahidah Arina Shamsuddin
    ;
    Nursakinah Abdul Karim
    ;
    Ahmad Radi Wan Yaakub
    ;
    Nur Hulwani Ibrahim
    ;
    Tijjani Adam
    ;
    Nor Azizah Parmin
    ;
    Nadiya Akmal Baharum
    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
    Effect of molasses-based wastewater irrigation on the rice yield and heavy metals uptake by Oryza sativa: a field study
    (AIP Publishing Ltd., 2023)
    Nuratikah Ghazali
    ;
    Ku Syahidah Ku Ismail
    ;
    Roslaili Abd Aziz
    ;
    Nyvee Inthano
    ;
    Ahmad Radi Wan Yaakub
    ;
    Md Nabil Ab Adzim Saifuddin
    ;
    Ng Hock Hoo
    ;
    Ayob Katimon
    The molasses-based effluent discharge contains significant amount of nutrients (e.g. Fe, Mg, K), which has potential use as an organic fertilizer to fit into the waste-to-wealth plan. Apart from that, the presence of toxic heavy metals content should not be underestimated as it could somehow end up in the rice grains and into the food chains. Thus, in this present work, the concentrations of Al, Cr, Cu and Ni in paddy crops from three different plots irrigated with the molasses-based effluent from an ethanol distillery; Control Plot, Plot 1 (repeatedly irrigated) and Plot 2 (irrigated for the first time) were investigated. All the heavy metals were found to be within the limits indicated by the Food and Agriculture Organization (FAO) for the reuse of wastewater for cultivation, Standard B in the Fifth Schedule, Environmental Quality (Industrial Effluent) Regulations 2009, and the Malaysia Ground Water Quality Standard (MGWQS) for Agricultural 2019 by the Department of Environment Malaysia. The results postulated that the rice yield in Plot 2 was higher compared to the other plots. The study also revealed that the concentrations of the heavy metals in the paddy plants decreased when mobilized from the roots to the rice grains for all sampling plots (p < 0.05). The bioconcentration factor (BCF) for Cu and Ni showed the highest values of 2.01 and 4.89, respectively in Plot 1. As the heavy metals concentration in wastewater were within the allowed limit, metals present in the paddy plant parts could be mobilized from the metals readily present in the soil. These results indicated that the molasses-based distillery’s effluent could be a source of plant nutrients as the rice yields improved and have potential to be used for paddy irrigation, as long as it is contained from leaching into water reservoirs.xc
  • Publication
    Soil risk assessment on the usage of molasses-based distillery effluent for paddy irrigation: heavy metals content
    (Springer, 2023)
    Nuratikah Ghazali
    ;
    Ku Syahidah Ku Ismail
    ;
    Roslaili Abd Aziz
    ;
    Ahmad Radi Wan Yaakub
    ;
    Md Nabil Ab Adzim Saifuddin
    ;
    Nyvee Inthano
    ;
    Ng Hock Hoo
    ;
    Ayob Katimon
    Heavy metal contamination in the soil is becoming a serious issue for food safety and human health. This study aims to quantify the concentration of cadmium (Cd), chromium (Cr), and lead (Pb) in paddy soil before and after irrigation with molasses-based distillery effluent in Perlis, Malaysia. Samples of effluent together with soil samples from two sampling plots were collected and analyzed using an inductively coupled plasma mass spectrometry (ICP-MS). It was found that the heavy metals in the effluent used for irrigation did not exceed the standard limit given by the Department of Environment (DOE) of Malaysia and the Food and Agriculture Organization (FAO) Standards for irrigation. Cr concentration was 0.01 mg/L, while Cd and Pb were not detected. The concentrations of heavy metals for the selected elements in paddy soil were also below the critical soil concentration enforced by the New York State Department of Environmental Conservation for normal soil. The heavy metal concentration’s contamination level was assessed by using the geoaccumulation index (Igeo) and the obtained data showed that all the selected elements can be classified as class 0 (uncontaminated). The results also showed that the Igeo before paddy planting was already high, and it might be due to anthropogenic activities. Pollution Load Index (PLI) values of all the soil samples were uncontaminated as the result showed PLI < 1. The study’s findings support the assertion that the soil samples were not significantly contaminated with the studied heavy metals before and after irrigation with molasses-based distillery effluent.
  • Publication
    Effect of latex coating on the physical properties of Calcium Alginate beads
    (Springer, 2023-09)
    Yee-Ming Peh
    ;
    Chee-Seng Lew
    ;
    Lee Boon Beng
    ;
    Farizul Hafiz Kasim
    ;
    Akmal Hadi Ma’Radzi
    ;
    Md Nabil Ab Adzim Saifuddin
    ;
    Ahmad Radi Wan Yaakub
    ;
    Mohd Asri Yusoff
    Alginate has been commonly applied in encapsulation due to its gelling capacity, biocompatibility, and environmentally friendly properties. Alginates can produce a thermally stable and biocompatible hydrogel in the presence of divalent cations such as calcium. However, the high porosity and low physical stability of calcium alginate beads can lead to encapsulation loss and degradation of encapsulated materials. It is speculated that latex coating on the beads can overcome the issues. Hence, this study aims to investigate the effect of latex coating on the physical properties of Ca-alginate beads. An extrusion dripping method was adopted to produce Ca-alginate beads. The beads were multilayer coated with a 5% latex solution. The size and shape of uncoated and coated beads were analyzed using 2D image analysis. The thickness of the latex coating layers was measured layer by layer using a thickness gauge. The results indicated that as the number of coating layers increased, the size of the beads also increased. However, the sphericity of the beads is decreased as the number of layers of latex coating is increased. The thickness of the latex coating increased layer by layer, from 0.017 mm to 0.112 mm. In short, the calcium alginate beads can be coated by latex. The diameter of the bead is significantly increased after two layers of latex coating, and the sphericity of the beads is reduced considerably after two layers of latex coating.
  • Publication
    Synthesis and characterization of reduced graphene oxide using the aqueous extract of Eclipta prostrata
    ( 2020-08-01)
    Chuah Regnant
    ;
    Subash Chandra Bose Gopinath
    ;
    Anbu P.
    ;
    Midhat Nabil Ahmad Salimi
    ;
    Ahmad Radi Wan Yaakub
    ;
    Lakshmipriya Thangavel
    In this study, biological deoxygenation of graphene oxide (GO) using an Eclipta prostrata phytoextract was performed via the infusion method. The presence of oxide groups on the surface of graphene and removal of oxides groups by reduction were characterized through morphological and structural analyses. Field emission scanning electron microscopy images revealed that the synthesized GO and rGO were smooth and morphologically sound. Transmission electron microscopy images showed rGO developing lattice fringes with smooth edges and transparent sheets. Atomic force microscopy images showed an increase in the surface roughness of graphite oxide (14.29 nm) compared with that of graphite (1.784 nm) due to the presence of oxide groups after oxidation, and the restoration of surface roughness to 2.051 nm upon reduction. Energy dispersive X-ray analysis indicated a difference in the carbon/oxygen ratio between GO (1.90) and rGO (2.70). Fourier-transform infrared spectroscopy spectrum revealed peak stretches at 1029, 1388, 1578, and 1630 cm−1 for GO, and a decrease in the peak intensity after reduction that confirmed the removal of oxide groups. X-ray photoelectron microscopy also showed a decrease in the intensity of oxygen peak after reduction. In addition, thermogravimetric analysis suggested that rGO was less thermally stable than graphite, graphite oxide, and GO, with rGO decomposing after heating at temperatures ranging from room temperature to 600 Â°C.
      3  13
  • Publication
    Assessment of heavy metals contamination studies in paddy grains around paddy field in Perlis
    ( 2020-11-02)
    Muhammad Nur Aiman Uda
    ;
    Uda Hashim
    ;
    Subash Chandra Bose Gopinath
    ;
    Uda, Muhammad Nur Afnan
    ;
    Ahmad Radi Wan Yaakub
    According to media reports, environmental pollution by heavy metals is harmful to the millions of people across the world. Apart from that, heavy metal accumulation may have an effect on animal and plants as well due to their toxicity. In agriculture sector, irrigation with high a toxicity of heavy metals will affect the growth of plant. Rice for example is grown in flooded fields thus are easily immobilized as compared to dryland crop. In fact, this heavy metal is readily available and become severe to paddy plant. Therefore, this study aims to quantify and focus on the concentrations of arsenic and zinc in paddy grains, where it will help a researcher to monitor and trace the amount of heavy metal in paddy field especially in paddy grains.
      5  24
  • Publication
    Diagnosing metabolic diseases by nanoparticle immobilization
    ( 2020-01-01)
    Nor Azizah Parmin
    ;
    Uda Hashim
    ;
    Subash Chandra Bose Gopinath
    ;
    Nadzirah S.
    ;
    Muhammad Nur Uda
    ;
    Muhammad Nur Aiman Uda
    ;
    Voon Chun Hong
    ;
    Isa A.M.
    ;
    Ahmad Radi Wan Yaakub
    Metabolic disease is a group of conditions that expand the risk of heart disease, stroke, and type 2 diabetes. High blood sugar, blood pressure, excess body fat around the waist, and abnormal cholesterol or triglyceride levels are included in this kind of metabolic disease that seems dangerous to human beings. The development of metabolic disease happened when the organs, such as the liver and pancreas did not function properly and triggered metabolic disease. Metabolic diseases happen at the point when irregular compound responses in the human body can modify the typical metabolic procedures. Metabolic diseases can be defined as an inherited single gene, mostly autosomal recessive. The principal classes of metabolic diseases include metabolic brain diseases, calcium metabolism disorder, acid-base imbalance, and glucose metabolism disorders. Diagnosing metabolic diseases was tedious and depending on which type of disease was involved, and currently, by using DNA tests, we can identify the disease but it takes several hours and only a professional person in charge can analyze the result. Advances in diagnosing metabolic diseases by nanoparticle immobilization establish a promising exploration area with favorable impacts on the treatment of diseases. Nanotechnology based on nanoparticle implementation was useful for the metabolic disorder diagnosis to prevent the disease from going viral to develop. Biosensor based on nanoparticles has been applied in several detections including metabolic illnesses to improve accessible analytical methods. Point-of-care (POC) sensor devices have been developed for metabolic disease and offer outcomes, quicker, simpler and at a lower cost than conventional methods. It also can be used in remote regions for metabolic diagnosis. In this chapter, different nanoparticle immobilization has been discussed to diagnose metabolic diseases by using it in clinical approach.
      4  34
  • Publication
    Isolation of cellulose nanocrystals from rice husks using natural deep eutectic solvent
    ( 2024-07)
    Nur Ain Natasya Ramli
    ;
    Sam Sung Ting
    ;
    Ahmad Radi Wan Yaakub
    ;
    Muhammad Faiq Abdullah
    Cellulose nanocrystals (CNCs) are highly crystalline, rod-shaped nanoparticles derived from cellulose, commonly found in biomass such as rice husks. Rice husks, an agricultural waste rich in cellulose, can be utilized for CNC production. In this study, CNCs were isolated from rice husks using a natural deep eutectic solvent (NADES), an environmentally friendly solvent. The objective was to examine the effects of temperature and reaction time on CNC solubility during dissolution with NADES. The one-factor-at-a-time (OFAT) method revealed that the optimal conditions were at temperature of 120°C and a reaction time of 8 hours. Morphological analysis using microscopy showed that raw rice husks had a rough, solid, brown appearance, while alkaline-treated rice husks appeared smoother and more porous. Bleached rice husks exhibited a very smooth, white, and fluffy appearance, and CNCs appeared as transparent solids. Fourier transform infrared (FTIR) analysis indicated the presence of β-glycosidic linkages in all three samples (CNCs, alkaline-treated, and bleached rice husks), suggesting that the cellulose structure remained intact during pretreatment. Antibacterial activity was evaluated using the disc diffusion method, confirming that raw, alkaline-treated, and bleached rice husks, as well as CNCs isolated from rice husks, exhibited antibacterial properties against both gram-negative bacteria (E. coli) and gram-positive bacteria (B. subtilis). This study successfully isolated CNCs from rice husks using NADES, demonstrating the potential for further improvements to enhance production efficiency.
      1  20
  • Publication
    Comparative study on mechanisms of gases release from Ca-alginate beads
    ( 2024)
    Yee-Ming Peh
    ;
    Lee Boon Beng
    ;
    Farizul Hafiz Kasim
    ;
    Akmal Hadi Ma’Radzi
    ;
    Ahmad Radi Wan Yaakub
    ;
    Hafizah Mohd Johar
    ;
    D.F.A. Riza
    ;
    N. Izza
    ;
    K. Gustinasari
    ;
    I.K. Maharsih
    ;
    W.B. Sunarharum
    ;
    M. Nurcholis
    ;
    B.S.D. Dewanti
    ;
    V.T. Widayanti
    ;
    E. Mufidah
    ;
    I. Qisthiya
    ;
    D. Karadag
    ;
    S. Idrus
    ;
    H. Umakoshi
    ;
    Y.C. Lee
    ;
    D. Fatchurrahman
    ;
    M. Zhu
    ;
    K.A. Omwange
    ;
    T. Addini
    Calcium alginate (Ca-alginate) beads have attracted considerable attention as carriers for the controlled release of volatile compounds due to their biocompatibility and tunable properties. This study aimed to compare the release of ethylene and carbon dioxide gas from Ca-alginate beads. Ca-alginate beads were prepared from a sodium alginate solution containing ethephon and calcium carbonate as the gas-forming agent. The resulting solution was then extruded into a calcium chloride solution. The gas release behavior was studied by monitoring the concentration of released gases over time using gas detectors. Extrusion tip diameter, alginate concentration and gas-releasing agent concentration were systematically varied to assess their effect on the gas release rate. The results indicated distinct release patterns for ethylene and carbon dioxide gas. Ethylene gas exhibited a relatively slower and sustained release, while carbon dioxide gas exhibited a more rapid release. Moreover, the bead size influenced the gas release, with larger beads displaying faster release rates for ethylene and carbon dioxide gas. The concentration of alginate also played a role in modulating the release kinetics, with higher alginate concentration resulting in slower gas release. The findings have implications for designing and optimizing Ca-alginate-based systems for agricultural applications, including plant hormone delivery and modified atmosphere packaging.
      1  41