Ruslinda A. Rahim
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Preferred name
Ruslinda A. Rahim
Official Name
Ruslinda, A. Rahim
Alternative Name
Rahim, R. A.
Ruslinda, A. Rahim
A. Rahim, Ruslinda
Rahim Ruslinda, A.
Ruslinda, Abdul Rahim
Rahim, Ruslinda Abdul
Ruslinda, A. R.
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Scopus Author ID
57194735807

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Immuno-probed graphene nanoplatelets on electrolyte-gated field-effect transistor for stable cortisol quantification in serum

2020-12-01 , Nur Nasyifa M.M. , Ruslinda A. Rahim , Abdul Halim N.H. , Zainol Abidin A.S. , Mohd Faudzi F.N. , Ahmad N.A. , Lockman Z. , Rezek B. , Kromka A. , Subash Chandra Bose Gopinath

Physiological and emotional stress affects the regulation of cortisol secretion, a routine process in circadian rhythm. Regular monitoring of cortisol level as a biomarker in the blood stream becomes vital to determine cortisol-related diseases. This study reports immuno-probed graphene nanoplatelets on electrolyte-gated field-effect transistor (EGFET) biosensor for cortisol determination in human serum. Solution-processed graphene nanoplatelets were evidenced on the surface by Raman spectroscopy analysis and utilized as the transducing element on the field-effect transistor. Further, confirmed the binding events of the antibody on graphene nanoplatelets using X-Ray Photoelectron Spectroscopy and characterized the electrostatic gating effect of cortisol and intermediate functionalization on graphene nanoplatelets-EGFET. The biosensor exhibited good sensitivity of 72.30 µA.(g/mL)−1 in a linear range between 1.00 pg/mL to 10.00 ng/mL, with a limit of detection (LOD) of 0.85 pg/mL. Confirmation with binding events on the biosensor was done using the relevant molecules, progesterone, cortisone, and corticosterone, and found to be selective towards cortisol. Cortisol was also successfully detected with interference by the human serum, suggesting the capability of graphene nanoplatelets-EGFET sensor for determining cortisol in a complex matrix.

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Measurement of rice moisture content based on quantitative analysis from radio tomography images

2024-05-01 , Nurul Amira Mohd Ramli , Mohd Hafiz Fazalul Rahiman , Ruslinda A. Rahim , Latifah Munirah Kamarudin , Latifah Mohamed , Moqbel Abdullah M.S. , Ammar Zakaria

Inefficient storage of paddy and rice grains can lead to grain deterioration, resulting in post-harvest losses ranging from 10% to 30%. The quality of grains cannot be improved throughout the storage period. Therefore, following the mechanisation of agricultural industries, air dryers have been developed to control the crops’ moisture level by blowing ambient or heated air into the silo to improve the aeration and allow the grains to be preserved with minimal loss of quality until the appropriate time for managing and marketing processes. However, the conventional sampling method used to measure the moisture level is inefficient because it is very localised and only represents part of the moisture distribution inside the bulk grains. Additionally, incorporating advanced technologies can be a significant cost limitation for small-scale industries. Thus, to address the issue, this research study developed a radio tomographic imaging (RTI) system in a silo-scale prototype using 20 sensor nodes operating at 2.4 GHz to localise and monitor the moisture level constructively. The RTI system reconstructs the cross-sectional images across the rice silo by measuring radio frequency attenuation, in terms of received signal strength (RSS) quality, caused by the rice moisture phantoms within the wireless sensor network (WSN) area. A total of five phantoms’ profiles having a percentage of moisture content (MC)of 15%, 20% and 25% were reconstructed using four image reconstruction algorithms,Linear Back Projection (LBP), Filtered Back Projection (FBP), Newton’s One-step ErrorReconstruction (NOSER) and Tikhonov Regularisation. Then, an image quality assessment,Mean Structural Similarity Index (MSSIM), was utilised to evaluate the performance of thereconstructed images. Lastly, a numerical method based on the first-order linear regressionmodel was introduced as a preliminary approach toward the method’s establishment. In summary, the experimental results demonstrated average image quality scores for all MClevels (15%, 20% and 25%), where the range scores are 0.2776 – 0.4755. Based on thenumerical analysis, the results support the possibility of engaging the proposed techniqueto monitor the moisture level inside a rice silo with the highest and lowest correlationcoefficients of 0.7218 and 0.5442, respectively.

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Dielectrophoresis as an adjunctive technique for fibroblast cell migration to enhance wound closure

2024-06 , Nur Nasyifa Mohd Maidin , Revathy Deivasigamani , Muhamad Ramdzan Buyong , Mohd Ambri Mohamed , Ruslinda A. Rahim

This study reports on DEP-based simulation and experimental validation of polystyrene (PS) beads and fibroblast cells for primary skin cell migration for enhancing wound closure. MyDEP software was used to calculate the numerical simulation of the Clausius-Mossotti factor (CMF). In order to examine particle trajectories based on input frequencies, the finite element technique (FEM) is used. The trajectories of PS beads and fibroblast cells were experimentally assessed to verify the impact of frequency applied on the polarisation of PS beads and fibroblast cells. The outcome illustrated the potential of employing FDEP to move particles and cells to regions of high and low electric field. Fibroblast cells exhibit negative dielectrophoresis (NDEP) at a broad range of frequencies. Thus, FDEP can be utilised for frequency optimisation to enhance wound closure.

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Surface Morphology Analysis of graphene transfer on SiO2 with BPA aptasensor detection using Electrochemical Impedance Spectroscopy

2023-01-01 , Shukri N.I.A. , Norhayati Sabani , Mohamad Faris Mohamad Fathil , Syarifah Norfaezah Sabki , Ruslinda A. Rahim , Halim N.H.A. , Ismail N.S.

Bisphenol A or BPA is one of the highest produced chemicals in the world. The production of polycarbonate plastic and epoxy resin are used to make variety of consumer goods and it is frequently employed BPA as a raw material. BPA is one of the endocrine disruptors which is related to a wide range of adverse health effects that can cause reproductive disorders and many kinds of cancers. In the work, the novelty of electrochemical sensor of BPA was constructed on a graphene modified electrode using graphene transfer method. In this work, High-power microscope and scanning electron microscopy were used to study the production and characterization of the graphene, with two significant mapping graphene at 20% and 80%. The existence of graphene on silicon oxide was analyzed using Raman Spectroscopy while the composition of the materials was analyze using Fourier-Transform Infrared Spectroscopy. In this analysis, both analysis data from Raman and FTIR clearly shown that 80% mapping graphene is the best option which resulting to the high surface coverage. The electrochemical performance of the mapping 80% graphene electrode was examined using Electrochemical Impedance Spectra. The increase in charge transfer resistance (Rct) both before and after the addition of BPA denotes the development of the charge at the electrode surface. The equivalent circuit shows the Rct of graphene increased from 0.4 k Ω to 1.2 k Ω and drastically increased to 300 kΩ when the device was introduced with BPA due to the existence of a negative charge carrier and the repelling contact.

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Fabrication of electrolyte-gate nanocrystalline diamond-based field effect transistor (NCD-EGFET) for HIV-1 Tat protein detection

2020-03-18 , Ahmad, Nurul Atiqah , Ruslinda A. Rahim , Nur Syakimah Ismail , Rezek B.

In this paper, we reported on the fabrication process of electrolyte-gate field effect transistor using nanocrystalline diamond as a sensing transducer. The fabrication procedure was begin with the growth of nanocrystalline diamond thin film on silicon/silicon dioxide (Si/SiO2) substrate using microwave plasma-enhanced chemical vapour deposition (CVD). Then the photolithography process was performed in order to design and pattern the field effect transistor device with the active gate channel of 60 m length and 20 m width. Each device consists of three active gate channel which connecting to three different pairs of source and drain contact. The surface morphology of fabricated NCD-EGFET was characterized using Scanning Electron Microscope to clarify the active gate channel of the device and the grain size of nanocrystaline diamond. The current-voltage (I-V) measurement of the device were carried out to study the electrical behaviour for HIV-1 Tat protein detection via RNA aptamer as sensing probe.

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Formation of polypropylene nanocomposite joint using silicon carbide nanowhiskers as novel susceptor for microwave welding

2023-05-01 , Foong P.Y. , Voon Chun Hong , Lim B.Y. , Teh P.L. , Mohd Afendi Rojan , Subash Chandra Bose Gopinath , Mohd Khairuddin Md Arshad , Nor Azizah Parmin , Low F.W. , Ruslinda A. Rahim , Uda Hashim

Up to present, no study has reported on the use of silicon carbide nanomaterials (SiCNMs) as susceptor for microwave welding of thermoplastics. Therefore, in this study, silicon carbide nanowhiskers (SiCNWs) was attempted as the microwave susceptor for the microwave welding of polypropylene (PP). It was observed that SiCNWs are capable of absorbing microwave and converting them into heat, leading to a sharp increase in temperature until it reaches the melting point of PP substrates. The microwave welded joint is formed after the molten PP at the interface between PP substrates is cooled under pressure. The effect of microwave heating duration and solid loading of SiCNWs suspension was studied and reported. The formation mechanism of SiCNWs reinforced PP welded joint was proposed in this study. With these remarkable advantages of microwave welding and enhanced mechanical properties of the welded joint, it is believed that this study can provide a new insight into welding of thermoplastic and material processing through short-term microwave heating.

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Electrochemical study of TiO2 thin film on aluminium electrode for glucose detection

2020-01-08 , Yen F.S. , Halim N.H.A. , Norhayati Sabani , Ruslinda A. Rahim , Nur Syakimah Ismail

This paper presents the fabrication of Interdigitated Electrodes (IDEs) towards the detection of glucose. The transducer is constructed based on IDE because of its single layer electrode structure. Majority of IDE used metal such as gold and nickel as the electrodes because of their excellent electrical performances. However, in this paper, aluminium is applied as metal of electrodes not only because of its stable material but also trying to investigate the interaction between aluminium metal and Titanium dioxide, TiO2 with glucose detection. Titanium dioxide has been utilized as thin film on the deposited aluminium electrodes to increase the interaction between aluminium electrodes with different concentration of glucose solution. The designs of IDEs interdigitated array (IDBA) and interdigitated ring array (IDRA) are performed by using AUTOCAD and it is printed on a transparency paper as a mask. Customary photolithography methods with positive resist are applied to transfer the pattern on a silicon wafer in this fabrication process. Then, the fabricated IDEs are viewed and examined under Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) to verify the surface morphology and topology. The electrochemical performance of IDEs is observed through cyclic voltammogram characteristics performed using potentiostat. In the nut shell, both IDBA and IDRA are tested within 0 to 100 mM range of glucose concentration.

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Designing DNA probe from HPV 18 and 58 in the E6 region for sensing element in the development of genosensor-based gold nanoparticles

2022-10-01 , Jaapar F.N. , Nor Azizah Parmin , Nur Hamidah Abdul Halim , Uda Hashim , Subash Chandra Bose Gopinath , Halim F.S. , Ruslinda A. Rahim , Voon Chun Hong , Muhammad Nur Aiman Uda , Muhammad Nur Afnan Uda , Nadzirah S. , Rejali Z. , Afzan A. , Zakaria I.I.

The E6 region has higher protuberant probability annealing than consensus probe focusing on another region in the human papillomavirus (HPV) genome in terms of detection and screening method. Here, we designed the first multiple virus single-stranded deoxyribonucleic acid (ssDNA) for multiple detections in an early phase of screening for cervical cancer in the E6 region and became a fundamental evolution of detection electrochemical HPV biosensor. Gene profiling of the virus ssDNA sequences has been carried by high-end bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST), and Clustal OMEGA in a row. The output from bioinformatics tools resulted in 100% of similarities between our virus ssDNA probe and HPV complete genome in the databases. The cross-validation between HPV genome and our designed virus ssDNA provided high specificity and selectivity during screening methods compared with Pap smear. The DNA probe for HPV 18, 5′ COOH-GAT CCA GAA GGT ACA GAC GGG GAG GGC ACG 3′, while 5′COOH-GGG CGC TGT GCA GTG TGT TGG AGA CCC CGA3′ as DNA probe for HPV 58 designed with 66.77% guanine (G) and cytosine (C) content for both. Our virus ssDNA probe for the HPV biosensor promises high sensitivity, specificity, selectivity, repeatability, low fluid consumption, and will be useful in mini-size diagnostic devices for cervical cancer detection.

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Effect of Microwave Power and Clamping Pressure on the Microwave Welding of Polypropylene Using Silicon Carbide Nanowhiskers as Microwave Susceptor

2022-01-01 , Foong P.Y. , Voon Chun Hong , Lim B.Y. , Teh P.L. , Mohd Afendi Rojan , Nor Azizah Parmin , Subash Chandra Bose Gopinath , Mohd Khairuddin Md Arshad , Low F.W. , Mahalingam S. , Manap A. , Ruslinda A. Rahim , Uda Hashim

Due to their excellent dielectric properties and the rapid response to microwave irradiation, silicon carbide nanowhiskers (SiCNWs) were employed as microwave susceptor in this study to absorb microwave and locally melt the surrounding polypropylene (PP) substrates for the joining of PP substrates. Complete welded joint is formed after the melted PP was cooled and resolidified. Other than microwave susceptor, SiCNWs also acted as the nanofillers in strengthening the welded joint through the formation of SiCNWs reinforced PP nanocomposite at the interface of PP substrates. Besides, the effect of microwave power on the microwave welding of PP substrates using SiCNWs as susceptor was studied and reported. It was found that the tensile strength and modulus of elasticity of the welded joint improved as microwave power increased. However, it deteriorates the flexibility of the welded joint as high stiffness SiCNWs were incorporated deeper into the PP matrix which restricted the PP chain mobility. Aside from microwave power, clamping pressure is also critical in determining the mechanical properties of a welded joint. When compared to unclamped welded joint, the tensile strength, modulus of elasticity and flexibility of welded joint subjected to clamping pressure improved drastically. Moreover, the tensile strength of welded joint increased when the clamping pressure was increased from P1 to P3, but decreased when the clamping pressure was further increased to P4 due to the occurrence of flashing at welded joint. The formation mechanism of SiCNWs reinforced PP welded joint was also proposed in this study. Compared to conventional welding, this welding process is easy, straightforward and is able to produce welded joint with outstanding mechanical properties via precise controlling of the processing parameters. Thus, microwave welding is thought to offer an option for the joining of thermoplastics and other applications.

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Field-Effect Transistor-based Biosensor Optimization: Single Versus Array Silicon Nanowires Configuration

2020-01-01 , Ong C.C. , Mohamad Faris Mohamad Fathil , Mohd Khairuddin Md Arshad , Mohammad Nuzaihan Md Nor , Ruslinda A. Rahim , Uda Hashim , Rafizatul Fitri Abdullah , Mohd Hazmi Mohd Ghazali , Tamjis N.

This paper demonstrated the effect of different number of silicon nanowire transducer channels, in other word single, double, and triple channels towards the performance of field-effect transistor-based biosensor through simulation tool. These silicon nanowire field-effect transistor biosensors were designed and simulated in device simulation modelling tool, Silvaco ATLAS with fixed length, width, and height of the silicon nanowire. Different negatively interface charge density values were applied on the transducer channels’ surface of the biosensors to represent as detected target biomolecules that will bind onto the surface of the transducer regions. Based on the results, more negatively interface charges density values presented on the sensing channels had reduced the electron carrier accumulation at the channel’s interface, therefore, reduced drain current flow between the source and drain terminal. With the increase number of the transducer channels, significant change in drain current for every applied negatively interface charges became more apparent and increased the sensitivity of the biosensor. The triple transducer channels silicon nanowire field-effect transistor biosensor had demonstrated highest sensitivity, that is 2.83 µA/e∙cm2, which indicates it has better response for the detection of interface charges, thus increases chances for transducer channels reaction to the target biomolecules during testing or diagnosis.

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