Now showing 1 - 10 of 15
  • Publication
    Advancing COVID-19 detection high-performance RNA biosensing via electrical interactions
    ( 2024-06) ;
    Muhammad Nur Afnan Uda
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    ; ;
    Nur Hulwani Ibrahim
    ;
    Chai Chang Yii
    ;
    Lorita Angeline
    This research paper investigated the detection of COVID-19 using an Aluminum Interdigitated Electrode (Al-IDE) sensor based on electrical conductivity. The silanization process involved the functionalization step, employing (3-Aminopropyl) triethoxysilane (APTES), while the immobilization process was facilitated by the RNA Probe specific to COVID-19. To verify its specificity in detection, the functionalized biosensor was tested against single-base mismatches, non-complementary sequences, and complementary sequences. The physical characteristics of the Al-IDE biosensor were examined using both low-power microscopy (LPM) and high-power microscopy (HPM). Additionally, the morphological properties of the biosensor were assessed using atomic force microscopy (AFM). To assess its diagnostic potential, the biosensor's sensitivity was evaluated by exposing it to a range of complementary targets, spanning from 1 femtomolar (fM) to 1 micromolar (μM). The current-voltage (I-V) characteristics of the biosensor were meticulously analyzed at each stage of functionalization bare Al-IDE, silanization, immobilization, and hybridization. This I-V characterization was carried out using a picoammeter voltage source (Keithley 2450), Kickstart software, and a probe station. The results confirmed the biosensor's capability to effectively detect COVID-19 targets within the nanoampere concentration range, demonstrating its success in detecting specific COVID-19 targets at the nanoampere level.
  • Publication
    Quantitative lead (Pb+) ion detection via modified silicon nanowire
    ( 2021-05-03) ; ;
    Nuri A KH Ehfaed
    ;
    Muhammad Nur Afnan Uda
    ;
    The study presented a functionalized silicon with (3-aminopropyl) triethoxysilane (APTES) to serve as a sensor for heavy metal detection. The amino-functionalized Si nanowires were tested against the heavy metal, lead (Pb). Due to the silicon electrochemical response towards the heavy metal ions, linear response to four different sources of water was observed. The results indicated that Pb can be detected with a high precision. Furthermore, confirmation was demonstrated using atomic absorption spectroscopy to determine the level lead content in the collected water source. Tab water (H2O), River H2O, Treated (H2O), DI (deionized) H2O and found the levels of 0.0859 mg/L, 0.0929 mg/L, 0.0052mg/L, 0.0023 mg/L with 5.8pA, 7.2pA, 4.6pA, 3.3pA current responses, respectively. Thus, with this high capability to discriminate water samples, the sensor potential can be employed for effective heavy metal detections and further be extended to a large sensor network in water treatment plant. A new microfluidic bonding material based on SU8 to implement electrical Nano chemical sensors for ions sensing, and an investigation of direct electrical measurement allowed for label free detection.. Thus, the study developed new room temperature bonding method using SU8 as an intermediate adhesive layer. The SU8 modified bonding was compared with non modified. The bond strength of SU8 modified was found to be stronger than ordinary plasma bonding under the same curing conditions. Overnight room temperature curing yields an average burst pressure of 420 kPa, which is more than adequate for many PDMS sensor devices. In contrast, non SU8 coated plasma bonded resulted in a burst pressure of only 174 KPa.
      2
  • Publication
    Green route synthesis of antimicrobial nanoparticles using sewage alga bloom
    ( 2023-01-01)
    H.M A.
    ;
    Muhammad Nur Afnan Uda
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    ;
    Arsat Z.A.
    ;
    Abdullah F.
    ;
    Muttalib M.F.A.
    ;
    Hashim M.K.R.
    ;
    ; ;
    Yaakub A.R.W.
    ;
    Ibrahim N.H.
    ;
    Parmin N.A.
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    Nanoparticles have a large surface area for their size and interact effectively with other particles. AgNPs may be created chemically, physically, or biologically. Biological techniques are considered the safest and cleanest since they use no toxic chemicals. Biological synthesis involves plant extracts, bacteria, fungus, algae, and other organisms. The algal production of AgNPs is of major interest. The abundance of algae and the ease with which it can be grown in a lab are two of the many reasons why it has become so popular as a nanoparticle production source. In this study, algae were employed as nanoparticles and antibacterial inhibitors against microbes.
      2
  • Publication
    Nanowires vibration properties
    ( 2024-03-21) ; ; ;
    Muhammad Nur Afnan Uda
    The vibration properties and the mechanical characteristic are important for the stability of electronics devices, particularly for Nano devices with high potential application. Silicon Nanowire show different properties from the corresponding bulk silicon. The understanding of its behaviour with reliable theoretical model explain the relation between size effect of the nanowire and the vibration frequency is significant to reveal the mechanical behaviour of the device is very important. Thus, this study, present the effect of small diameter of Silicon Nanowires on Its Vibration Properties is established based on the lattice parameters and the binding energy change of silicon nanowire based on first principles calculations through Abinit. Atomic interaction of the SiNWs obtained based on the density functional theory. It was observed that the atomic interaction energy as result of electromechanically induced pressure due -hole pair in which electron (e-) was reductive, and hole (h+) was oxidative. The hole (h+) reacted with e- in the second nanowire, generating free radicals (e-), superoxide anion and perhydroxyl radicals which create phonon group velocity this create vibration. Due to the excessive energy of process the temperature rises and alters the atomic cubic dimensions in turn affect its elastic properties. The nanowire compared with with bulk silicon exhibit high higher modulus, this as result of damped behaviour of the nanowire which is due to the high frequency vibration of silicon atoms at the edge of SiNWs and its Debye length is shorter. As the wire diameter decrease effect of the atomic vibration is reduced.
      2
  • Publication
    Determination of silicon nanowire mechanical properties by first principle
    ( 2021-05-03) ; ;
    Muhammad Nur Afnan Uda
    ;
    Electronic and mechanical properties of SiNWs were studied based on First principle method via density functional theory. Effect of orientations on mechanical properties of silicon nanowire were identified. The elastic properties of {110}, {100}, {011} and {111} orientations were calculated. Due to atomic interaction in wires, various mechanical properties of wire changes were noted. The results show for strain 0.1164×10-5, 0.12×10-5 and 0.115×10-5 with modulus of 149.6GPa, 75.5GPa and 85.1GPa respectively.
      5  1
  • Publication
    Conductometric immunosensor for specific Escherichia coli O157:H7 detection on chemically funcationalizaed interdigitated aptasensor
    ( 2024)
    Muhammad Nur Afnan Uda
    ;
    Alaa Kamal Yousif Dafhalla
    ;
    Thikra S. Dhahi
    ;
    ; ;
    Asral Bahari ambek
    ;
    ; ;
    Nur Hulwani Ibrahim
    ;
    Escherichia coli O157:H7 is a strain of Escherichia coli known for causing foodborne illness through the consumption of contaminated or raw food. To detect this pathogen, a conductometric immunosensor was developed using a conductometric sensing approach. The sensor was con-structed on an interdigitated electrode and modified with a monoclonal anti-Escherichia coli O157: H7 aptamer. A total of 200 electrode pairs were fabricated and modified to bind to the target molecule replica. The binding replica, acting as the bio-recognizer, was linked to the electrode surface using 3-Aminopropyl triethoxysilane. The sensor exhibited excellent performance, detecting Escherichia coli O157:H7 in a short time frame and demonstrating a wide detection range of 1 fM to 1 nM. Concentrations of Escherichia coli O157:H7 were detected within this range, with a minimum detection limit of 1 fM. This innovative sensor offers simplicity, speed, high sensitivity, selectivity, and the potential for rapid sample processing. The potential of this pro-posed biosensor is particularly beneficial in applications such as drug screening, environmental monitoring, and disease diagnosis, where real-time information on biomolecular interactions is crucial for timely decision-making and where cross-reactivity or interference may compromise the accuracy of the analysis.
      4  24
  • Publication
    Integrated ZnO-Al2O3 nano particles as absorbent for heavy metal ions and organic impurities
    ( 2021-05-03) ; ;
    Mohan Mugguntan
    ;
    Muhammad Nur Afnan Uda
    ;
    Nanotechnology is an emerging interdisciplinary technology that has been booming in many areas during recent decade. The objective of this work was to verify Activated Alumina for removal of heavy metal arsenic with designed filtration unit. Alumina and Zinc oxide nanoparticles were successfully synthesized using both sol-gel and chemical techniques. This study is mainly focused on the synthesis method of Al2O3-NPs using two different type of acids namely sulphuric acid and hydrochloric acid with the base NaOH and KOH. The water treatment filtration unit designed using AutoCAD software. The alumina is prepared to remove heavy metals, especially arsenic from drinking water in order to obtain clean water. Chemical synthesis method of ZnO-NPs was carried out using prepared sodium hydroxide and zinc nitrate heptahydrate zinc acetate. The samples were characterized by different techniques such as Fourier transform infrared spectra (FTIR) and UV-vis. The average crystallite size of synthesized alumina range from 7.1 to 28 nm.
      4
  • Publication
    Electrical and topography analysis of 50 μm gap aluminium based interdigitated electrode
    ( 2024-03-21) ; ;
    Muhammad Nur Afnan Uda
    ;
    The aim of this research study is to study the electrical and topography analysis of fabricated Aluminium Interdigitated Electrode (Al IDE). Al IDE pattern was designed using AutoCAD software with 50 μM finger gap. Fabricated electrode was physically characterized using High Power Microscope (HPM), Scanning Electron Microscope (SEM) and electrically validated through I-V measurement using Current Source Meter (Keithley 2450) and sensor platform. Electrical measurement confirmed that Al IDE was well fabricated without any shortage and results of similar Al IDE samples were confirmed that the repeatability of the device.
      2
  • Publication
    MPTES decorated IDE for arsenic (AS) selective detection
    ( 2021-05-03) ; ;
    Mosbah A.B.
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    ;
    Muhammad Nur Afnan Uda
    Heavy metals ions are ions which generally occupied most part water sources such river, sea and other water flow channels such as drainage, water pipe. The exist of the ions in drinking water traces have called the attention researchers due to the recent discovery of the ions problem in both human health and aquatic animal such as fish. Fish come and encounter heavy metals ions in the river and ingest it and subsequently this fish eaten by man. The ions will pass to human and attack some human orgains. Finding the reliable solution to detect traces of heavy metals ions in water is a promising approach to eliminate such problems. This research aim is to enhance detection of heavy sensors, for sensor technology industry using the fabricated MTES surface-modified silicon interdigitated electrode to detect arsenic ion in water, The device was fabricated using conventional photolithography process coupled with deep RIE etching. The fabricated devices was modified surface and characterized by Scanning Electron Microscopy, Atomic Force Microscopy and high-power microscopy. The electrical analysis by applying voltage to measure the device response to the surface modification step and subsequently against arsenic ion as it bonded to the device via MPTES, various MTES concentrations distinguished against the bare device and arsenic concentration. Based on current and voltage analysis, concentration-dependent results were obtained, the detection limit for surface modified IDE to the arsenic detection was 20 pM with the linear response behaviour to the concentration, Thus, with this wonderful detection limits, the devices high high-performance characteristic by selectively distinguish arsenic ions against other foreign elements in the water.
      7
  • Publication
    High accuracy voltage amplifier electronic reader for two electrode electrical biosensor
    ( 2024-03-21)
    Muhammad Nur Afnan Uda
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    ; ;
    Low current output detection based electronic reader are the key factor for biosensors commercialization. Two type electrode based amperometric biosensors show low current signal output around nanoampere (pA) to microampere (μA) range. In this research, an electronic reader system with voltage converter, voltage amplifier, main control circuit and LCD display was developed to detect current output value for two type electrode amperometric biosensors in selectable ranges of nanoampere. The current source module will act as a replacement for the biosensor input current. The experiment was to verified the electrical functionality measurements of the device by comparing the accuracy of the electronic reader with Keithley 2450 source meter. The Design Spark PCB software and LTspice software were used to design the electronic reader circuit. Arduino software was used to create a programming code to upload in NodeMCU microcontroller.
      4