Now showing 1 - 10 of 54
  • Publication
    Design and Fabrication of Multichannel PDMS Microfluidic
    ( 2021-12-14) ; ;
    Muhammad Nur Afnan Uda
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    Thivina V.
    Microfluidic delivers miniaturized fluidic networks for processing liquids in the microliter range. In the recent years, lab-on-chip (LOC) is become a main tool for point-of-care (POC) diagnostic especially in the medical field. In this paper, we presented a design and fabrication on multi disease analysis using single chip via delivery of fluid with the multiple transducers is the pathway of multi-channel microfluidic based LOC's. 3 in 1 nano biosensor kit was attached with the microfluidic to produce nano-biolab-on-chip (NBLOC). The multi channels microfluidic chip was designed including the micro channels, one inlet, three outlet and sensor contact area. The microfluidic chip was designed to include multiplex detection for pathogen that consists of multiple channels of simultaneous results. The LOC system was designed using Design Spark Mechanical software and PDMS was used as a medium of the microfluidic. The microfluidic mold and PDMS microfluidic morphological properties have been characterized by using low power microscope (LPM), high power microscope (HPM) and surface profiler. The LOC system physical was experimental by dropping food coloring through the inlet and collecting at the sensor contact area outlet.
  • Publication
    Gold Nanoparticles Enhanced Electrochemical Impedance Sensor (EIS) for Human Papillomavirus (HPV) 16 Detection E6 region
    ( 2020-07-09)
    Amrul Muhadi A.S.
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    Rejali Z.
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    Afzan A.
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    Muhammad Nur Afnan Uda
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    Hong V.C.
    The persistent infection by high risk HPV is a necessary but not sufficient cause of this cancer which develops over a long period through precursor lesions which can be detected by electrochemical impedance sensor. The HPV driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of women with HPV related cervical disease and these biomarkers can also be used to increase the positive predictive value of current methods. The most influential methods for the detection and identification of HPV using gold nanoparticle (GNP) included electrochemical impedance sensor will visit their sensitivity, selectivity and characteristic detection on synthetic target which are complement of the DNA, non-complement of the DNA and mismatch of the DNA. In difference concentration of synthetic target, which stage can get the exactly value to determine the HPV in strain 16 was evaluated in this research studies.
  • Publication
    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.
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    Halim F.S.
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    Muhammad Nur Afnan Uda
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    Nadzirah S.
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    Rejali Z.
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    Afzan A.
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    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.
  • 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.].
  • 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
    Voltammetric DNA Biosensor for Human Papillomavirus (HPV) Strain 18 Detection
    ( 2020-07-09)
    Mhd Akhir M.A.
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    Rejali Z.
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    Afzan A.
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    Muhammad Nur Afnan Uda
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    This research was developed to focus on the study of the voltammetric DNA biosensor for the detection of HPV strain 18. In this research, electrical DNA biosensor was expected to detect HPV strain 18 more efficiently by using electrical characterization. In this project, device inspection was conducted to make sure the functional of the gold interdigitated electrode (IDE) by using Scanning Electron Microscope (SEM). 3-Aminopropyl Triethoxysilane (APTES) solution was used for the process of surface modification to form the amine group on the surface of the device to facilitate the attachment of the DNA probe. In this project, synthetic DNA sample and DNA from the saliva of several Biosystems Engineering students were used as the target DNA. The current-voltage (I-V) electrical characterization was conducted to detect the presence of HPV strain 18 in both DNA samples. As the results, perfect alignment between the electrodes on the IDE was detected under SEM. Surface modification of the biosensor successfully conducted which is the covalent bond between APTES and DNA probe increase the electrical. Synthetic DNA shows the presence of HPV strain 18 while there was no HPV strain 18 detected in the DNA from saliva samples.
  • Publication
    Distinguishing normal and aggregated alpha-synuclein interaction on gold nanorod incorporated zinc oxide nanocomposite by electrochemical technique
    Misfolding and accumulation of the protein alpha synuclein in the brain cells characterize Parkinson's disease (PD). Electrochemical based aluminum interdigitated electrodes (ALIDEs) was fabricated by using conventional photolithography method and modified the surfaces with zinc oxide and gold nanorod by using spin coating method for the analysis of PD protein biomarker. The device surface modified with gold nanorod of 25 nm diameter was used. The bare devices and the surface modified devices were characterized by Scanning Electron Microscope, 3D-Profilometer, Atomic Force Microscope and high-power microscope. The above measurement was also performed to measure the interaction of antibody with aggregated alpha-synuclein for normal, aggregated and aggregated alpha synuclein in human serum and distinguished against 3 control proteins (PARK1, DJ-1 and Factor IX). The detection limit for normal alpha synuclein was 1 f. with the sensitivity of 1 f. on a linear regression (R2 = 0.9759). The detection limit for aggregated alpha synuclein was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9797). Also, the detection limit of aggregated alpha synuclein in serum was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9739). These results however indicate that, serum has only minimal amount of alpha synuclein.