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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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.

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Effect of latex coating on the physical properties of Calcium Alginate beads

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.

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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.

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Effect of Process Variables on Gas Release from Free and Latex-Coated Calcium Alginate Beads

2024 , Yee-Ming Peh , Lee Boon Beng , Farizul Hafiz Kasim , Akmal Hadi Ma’Radzi , Sakthi Balaji , Ahmad Radi Wan Yaakub , Hafizah Mohd Johar , Mohd Asri Yusoff

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Effect of molasses-based wastewater irrigation on the rice yield and heavy metals uptake by Oryza sativa: a field study

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

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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.

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Bio-Enzyme Hybrid with Nanomaterials: A Potential Cargo as Sustainable Biocatalyst

2023-05-01 , Tan W.Y. , Subash Chandra Bose Gopinath , Anbu P. , Ahmad Radi Wan Yaakub , Subramaniam S. , Chen Y. , Sasidharan S.

With advancements in bionanotechnology, the field of nanobiocatalysts has undergone rapid growth and revolutionized various nanomaterials as novel and fascinating nanocarriers for enzyme immobilization. Nanotubes, nanofibers, nanopores, nanoparticles, and nanocomposites have been successfully developed and used as nanocarriers. The construction of robust nanobiocatalysts by combining enzymes and nanocarriers using various enzyme immobilization techniques is gaining incredible attention because of their extraordinary catalytic performance, high stability, and ease of reusability under different physical and chemical conditions. Creating appropriate surface chemistry for nanomaterials promotes their downstream applications. This review discusses enzyme immobilization on nanocarriers and highlights the techniques, properties, preparations, and applications of nanoimmobilized enzymes.

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Soil risk assessment on the usage of molasses-based distillery effluent for paddy irrigation: heavy metals content

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.

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Analysis on Silica and Graphene Nanomaterials Obtained From Rice Straw for Antimicrobial Potential

2024-06-12 , Muhammad Nur Aiman Uda , A Jalil N.H. , Muhammad Firdaus Abdul Muttalib , Fadhilnor Abdullah , Uda Hashim , Subash Chandra Bose Gopinath , Afnan Uda M.N. , Shahidah Arina Shamsuddin , Norizah Abd Karim , Ahmad Radi Wan Yaakub , Ibrahim N.H. , Tijjani Adam , Nor Azizah Parmin , Baharum N.A.

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.

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Characterization and anti-bacterial potential of iron oxide nanoparticle processed eco-friendly by plant extract

2020-11-02 , Yan, Leong Poh , Subash Chandra Bose Gopinath , Anbu P. , Farizul Hafiz Kasim , Hanna Ilyani Zulhaimi , Ahmad Radi Wan Yaakub

This research comprehends iron-oxide nanoparticle (IONP) production, the apparent metallic nanostructure with unique superparamagnetic properties. Durian-rind-extract was utilized to synthesize IONP and the color of reaction mixture becomes dark brown, indicated the formation of IONPs and the peak was observed at ∼330 nm under UV-visible spectroscopy. The morphological observation under high-resolution microscopies has revealed the spherical shape and the average size (∼10 nm) of IONP. The further support was rendered by EDX-analysis showing apparent iron and oxygen peaks. XRD results displayed the crystalline planes with (110) and (300) planes at 2θ of 35.73° and 63.53°, respectively. XPS-data has clearly demonstrated the presence of Fe2P and O1s peaks. The IONPs were successfully capped by the polyphenol compounds from durian-rind-extract as evidenced by the representative peaks between 1633 and 595 cm−1 from FTIR analysis. The antimicrobial potentials of IONPs were evidenced by the disk-diffusion assay. The obtained results have abundant attention and being actively explored owing to their beneficial applications.

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