Now showing 1 - 9 of 9
  • Publication
    Gold nanogap impedimetric biosensor for precise and selective Ganoderma boninense detection
    Ganoderma species are common wood-rotting fungi that cause root and stem rot in most monocots, dicots, and gymnosperms. It influences plantation crops such as oil palm and rubber in Malaysia, but the effects vary greatly within the genus. Because of the complex chemistry of Ganoderma, extracting and identifying the physiologically active chemicals is often time-consuming and necessitates extensive bioassays. This study investigated the specific identification of the most infectious Ganoderma species using a sub-20-nm gold electrode. Three electrodes were created using chemically controlled etching (2, 10, and 20 nm). An AutoCAD mask containing nanogap pad electrodes was used to create a chrome glass surface, which was then translated and built. Following the successful construction of the device, the sensor was evaluated using a combination of conventional photolithography and a size reduction technique to imprint the nanogap design onto the gold surface. Ganoderma boninense target DNA was synthesised and surface-modified to enable interaction at extremely low molecular concentrations. The proposed device has a detection limit of 0.001 mol/L, which is seven times lower than the detection limits of currently available devices. The capacitance, conductivity, and permittivity of complementary, non-complementary, single mismatched, and targeted biomolecules changed during hybridization. This sensor correctly differentiated between all samples. The sensor's performance is further validated by comparing experimental data from the sensor to theoretical data from the sensor's corresponding circuit model. The two data sets are very similar.
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  • Publication
    Novel Approaches in Fabrication and Integration of Nanowire for Micro/Nano Systems
    Nanowires have been utilized widely in the generation of high-performance nanosensors. Laser ablation, chemical vapor, thermal evaporation and alternating current electrodeposition are in use in developing nanowires. Nanowires are in a great attention because of their submicron feature and their potentials in the front of nanoelectronics, accelerated field effect transistors, chemical- and bio-sensors, and low power consuming light-emitting devices. With the control of nanowire size and concentration of dopant, the electrical sensitivity and other properties of nanowires can be tuned for the reproducibility. Nanowires comprise of arrays of electrodes that form a nanometer electrical circuit. One of advantages of nanowires is that they can be fabricated in nanometer-size for various applications in different approaches. Several studies have been conducted on nanowires and researchers discovered that nanowires have the potential in the applications with material properties at the nanometer scale. The unique electrical properties of nanowires have made them to be promising for numerous applications. Nowadays, for example, MOS field-effect transistors are largely used as fundamental building elements in electronic circuits. Also, the dimension of MOS transistors is gradually decreasing to the nanoscale based on the prediction made by Moor's law. However, their fabrication is challenging. This review summarized different techniques in the fabrication of nanowires, global nanowire prospect, testing of nanowires to understand the real electrical behavior using higher resolution microscopes, and brief applications in the detection of biomolecules, disease such as corona viral pandemic, heavy metal in water, and applications of nanowires in agriculture.
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  • Publication
    The importance, benefits, and future of nanobiosensors for infectious diseases
    ( 2024-04-01)
    Dhahi T.S.
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    Dafhalla A.K.Y.
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    Saad S.A.
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    Zayan D.M.I.
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    Ahmed A.E.T.
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    Elobaid M.E.
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    Infectious diseases, caused by pathogenic microorganisms such as bacteria, viruses, parasites, or fungi, are crucial for efficient disease management, reducing morbidity and mortality rates and controlling disease spread. Traditional laboratory-based diagnostic methods face challenges such as high costs, time consumption, and a lack of trained personnel in resource-poor settings. Diagnostic biosensors have gained momentum as a potential solution, offering advantages such as low cost, high sensitivity, ease of use, and portability. Nanobiosensors are a promising tool for detecting and diagnosing infectious diseases such as coronavirus disease, human immunodeficiency virus, and hepatitis. These sensors use nanostructured carbon nanotubes, graphene, and nanoparticles to detect specific biomarkers or pathogens. They operate through mechanisms like the lateral flow test platform, where a sample containing the biomarker or pathogen is applied to a test strip. If present, the sample binds to specific recognition probes on the strip, indicating a positive result. This binding event is visualized through a colored line. This review discusses the importance, benefits, and potential of nanobiosensors in detecting infectious diseases.
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  • Publication
    Interactive model for DNA specificity and selectivity and biosensor validation
    ( 2020-09-21)
    Dhahi T.S.
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    Specific and selective detection of biomolecule has become major research quest of scientist community, most diseases are curable however, early specific detection and selective nature determine this capabilities, thus need rogue sensor specificity and selectivity testing. Sensor specificity/selectively largely depend on the robust validation approach adopted. This paper presents the interactive Model for DNA Specificity and Selectivity in Biosensor Validation. The partial charge induced due to hybridization of complementary ssDNAs caused a significant change in the conductance of sensor specific potential. The interactive model of inorganic and organic behaviour was calculated based on first principle. The partial charge due to ssDNA and dsDNA molecule was computed using molecular dynamics (MD) simulation. The results show that, the full and identification of compliment, mismatched with precise sequence of acid bonds with specific time response of 1016 and 1020 for 0.0095 ns, 0.008nS respectively. With this fast and accurate response, the model could be used for the biosensor validation.
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  • Publication
    Recent advances in techniques for fabrication and characterization of nanogap biosensors: A review
    Nanogap biosensors have fascinated researchers due to their excellent electrical properties. Nanogap biosensors comprise three arrays of electrodes that form nanometer-size gaps. The sensing gaps have become the major building blocks of several sensing applications, including bio- and chemosensors. One of the advantages of nanogap biosensors is that they can be fabricated in nanoscale size for various downstream applications. Several studies have been conducted on nanogap biosensors, and nanogap biosensors exhibit potential material properties. The possibilities of combining these unique properties with a nanoscale-gapped device and electrical detection systems allow excellent and potential prospects in biomolecular detection. However, their fabrication is challenging as the gap is becoming smaller. It includes high-cost, low-yield, and surface phenomena to move a step closer to the routine fabrications. This review summarizes different feasible techniques in the fabrication of nanogap electrodes, such as preparation by self-assembly with both conventional and nonconventional approaches. This review also presents a comprehensive analysis of the fabrication, potential applications, history, and the current status of nanogap biosensors with a special focus on nanogap-mediated bio- and chemical sonsors.
      2
  • Publication
    Nanosensors: Recent perspectives on attainments and future promise of downstream applications
    ( 2022-06-01) ;
    Dhahi T.S.
    Nano Sensors are sensing devices with a dimension of less than or equal to 100 nm. They are incredibly tiny devices that transform physical, chemical, or biological substances into detectable signals. Because of this device's capacity to detect physical and chemical changes, nanotechnology has emerged as a technology of choice in a variety of industries. The device provides efficient and cost-effective methods for detecting and measuring chemical and physical characteristics. This overview discusses the status of Nano Sensors, as well as their accomplishments and potential applications toward downstream targets in medical, security, agriculture as well in Covid-19 detection. The paper provides a summary and critical analysis of various architectures (structures) employed in the development and use of Nano Sensors. Surface engineering is used to generate diverse chemistries for both general and specialised purposes. We derived fresh findings from available data on the mechanism, prospective development of various structures, approaches, and applications, and highlighted the contrasts and similarities in their characteristics and working processes. The review further summarised ability and future expected of this sensor in dealing with the various challenges where different nano sensors, types, fabrication techniques and applications with highlighted novelties of these techniques and applications are presented.
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  • Publication
    Nanogap nanowires and its applications in biosensing
    ( 2024-06-01)
    Dafhalla A.K.Y.
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    Dhahi T.S.
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    Al-Mufti A.W.
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    Saad S.A.
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    Alqahtani A.S.
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    Al-nuaimi M.A.H.
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    Nanogap nanowires have gained attention for their potential applications in biosensing due to their unique physical properties, such as high surface-to-volume ratios and enhanced sensitivity. These nanowires can be used as electrodes in electrochemical biosensors, improving the sensitivity and selectivity of these devices. They can also be integrated into sensor platforms using mature nano-fabrication procedures. These advancements offer great potential for developing highly sensitive and accurate biosensors for various applications, including biomedical diagnostics, environmental monitoring, and food safety. Nanogap nanowires have revolutionized the field by providing enhanced sensitivity and accuracy in detecting biological molecules. They have also been used in the fabrication of segmented nanowires for chemical sensing, allowing for more precise and targeted detection of specific analytes. Nanogap nanowires have shown promise in protein biomarker analysis, enabling ultra-sensitive detection of protein biomarkers at low levels. This review provides an overview of recent advancements in Nanogap Nanowires and their applications in biosensing.
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  • Publication
    Fabrication of 110 Silicon Nanowire Oriented with Direct Band Gap
    ( 2020-12-18) ;
    Dhahi T.S.
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    Rosli K.A.
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    Jaafar M.
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    Jaafar R.
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    Husin M.F.C.
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    Hashim M.N.
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    Rejab M.R.A.
    Today, the challenges of getting fast switching semiconductor device based device is the phonon generation mechanism for light-emitting by device such as diodes. The increase in efficiency of the device determine by the green light part of the emitted light spectrum. Silicon nanowire growth in the direction of 110 structure has indirect band gap, which tremendously improved the green emission efficiency at the lower Nano regime. Several band structure calculations have be predicted direct band for 110 growth silicon nanowire. Thus, the study report the fabrication of silicon nanowires with diameter between 20 to 50nm which demonstrate the direct nature of the band gap. A strong photoluminescence at wave spectrum of 597 nm with micro-second lifetime indicating it direct band gap. This study have demonstrated new nanostructure engineering based on silicon nanowire orientation which will allow new ways getting silicon nanowire functionality.
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  • Publication
    Advances in nano sensors for monitoring and optimal performance enhancement in photovoltaic cells
    ( 2024-04-19)
    Dhahi T.S.
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    Yousif Dafhalla A.K.
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    Tayfour O.E.
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    Mubarakali A.
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    Alqahtani A.S.
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    Tayfour Ahmed A.E.
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    Elobaid M.E.
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    Nanosensors have gained significant attention in recent years for improving energy conversion and storage performance in solar cells. These nanosensors, typically made from nanoparticles or nanowires, can be embedded within the solar cell to monitor parameters like temperature and light intensity. By monitoring these parameters, nanosensors provide real-time feedback and control to optimize the efficiency and performance of the solar cell. They also play a role in detecting potential issues, such as defects, for proactive maintenance and troubleshooting. The integration of nanosensors in solar cells enables the development of smart energy systems, leading to increased power output, improved stability, and a longer lifespan of solar cells. The deployment of nanosensors in solar cells offer promising trajectory for advancing energy conversion, utilization, and storage capabilities. This review summarizes recent advances in nanosensors in solar cells, with a focus on the role they play in enhancing energy conversion, utilization, and storage performance.
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