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Shahidah Arina Shamsuddin
Preferred name
Shahidah Arina Shamsuddin
Official Name
Shahidah Arina, Shamsuddin
Alternative Name
Shamsuddin, Shahidah Arina
Main Affiliation
Scopus Author ID
54785057000
Researcher ID
FWR-5498-2022
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1 - 3 of 3
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PublicationGold-nanoparticle associated deep eutectic solution mediates early bio detection of ovarian cancer( 2025-01)
;S. Uvambighai Devi ;N. Fareezah Jaapar ;F. Syakirah HalimGold nanoparticles (AuNPs) have indeed been extensively researched in biological and photothermal therapy applications in recent years. This study aims to enhance the sensitivity of biosensors for early detection of ovarian cancer biomarkers by investigating the efficacy of DES-mediated surface functionalization of AuNPs. Additionally, the impact of DES on the stability and dispersion of AuNPs on SiO2 support is assessed to optimize sensor performance. A simple DES-mediated synthesis method for efficient amine surface functionalization of silicon dioxide (SiO2) to incorporate tiny AuNPs for antibody biosensors. Physical characterization [Scanning Electron Microscope (SEM), Ultraviolet-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and 3D Profiler] and electrical characterization (Keithley) have been done to determine the functionalization of the modified IDE surface. SEM analysis indicated the resultant nanoparticles have truncated spherical shapes. There is just a peak recorded by UV-Vis at 504-540 nm with AuNPs due to the formation of monodispersed AuNPs. When the conjugation of DES with samples is measured, the curves are identical in form, and the highest peak after conjugation has remained at 230 nm but the SPR absorption peak becomes narrower and moves toward greater wavelengths, indicating the conjugation between the molecules. Furthermore, when the DES is conjugated with AuNPs, 3-Aminopropyltriethoxysilane (APTES), antibody, and protein, the peaks gradually increased and became narrower, where O-H at 3280 cm-1, C-H at 2809 cm-1 and 2933 cm-1, CH2 at 1448 cm-1, CH3 at 1268 cm-1, C-OH at 1048 cm-1 and 1110 cm-1 and C-N+ at 844 cm-1 as analyzed by FTIR. Moreover, it can be observed that the 3D profilometer revealed a few red-colored areas, which are the portion that protrudes from the IDE surface. Based on the findings, it is possible to infer that this immunosensor does have the prospective to be used in clinical investigations for the precise detection of ovarian cancer or other biomarkers. The capacitance, transmittance, and resistivity profiles of the biosensor clearly distinguished between the antibody immobilization and the affinity binding. The presence of a DES-mediated synthetic approach increased the possibility of supporting different metal nanoparticles on SiO2 as the potential platform for biosensor applications. -
PublicationAluminium interdigitated electrode with 5.0 μm gap for electrolytic scooting( 2024-06)
;Ismail Saad ;G. Yashni ;Nur Hulwani Ibrahim ;N. ParimonM. F. H. RaniThe goal of the research project is to design, fabricate, and characterize an extremely sensitive biosensor for use in healthcare. Using AutoCAD software, a novel IDE pattern with a 5 μm finger gap was created. Conventional photolithography and regular CMOS technology were used in the fabrication process. A 3D nano profiler, scanning electron microscopy (SEM), high-power microscopy (HPM), and low-power microscopy (LPM) were used to physically characterize the manufactured IDE. Chemical testing was done using several pH buffer solutions, and electrical validation was performed using I-V measurements. The Al IDE was produced, with a tolerance of 0.1 μm between the fabricated IDEs and the design mask. Electrical measurements verified the flawless fabrication of the IDE, and the device's repeatability was validated by the outcomes of comparable IDE samples. For each pH buffer solution, a modest additional volume of 2 μl was used to quantitatively detect slight current fluctuations in the microampere range. Through pH calibration for advanced applications in the realm of chemical sensors using an amperometric method, this research study has verified the chemical behavior of the IDE. -
PublicationSynthesis and optimization of Anodic Aluminium Oxide thin film electrode for DNA sensingRecent years, anodic aluminum oxide (AAO) has been extensively explored as an inexpensive, portable and sensitive DNA biosensing device. Apart from their ability to self-grow into well-ordered nanoporous with high porosity and huge surface area, AAO has one special feature wherein their nanopores‘ dimension are capable to be altered and engineered by controlling the main anodizing parameters namely voltage, temperature, time and electrolyte concentration. Since sensitivity and limit of detection of AAO-DNA biosensor depends on the nanopores‘ dimension itself, therefore, many researchers have tried to understand the effect of each anodizing parameters to the nanopores‘ dimension while tried to optimize and improve the sensitivity of AAO in detecting DNA. However, those studies were only focused on the trend of single variable parameter at one time by one-factor-at-a-time method (OFAT), rather than investigating all the interactions between the anodizing parameters simultaneously. Hence, they only reported the improvement made to the sensitivity of their AAO-DNA biosensor at the particular parameter range that they have tested without providing the best of optimum combination levels of all anodizing parameters while the most critical and influential anodizing parameter is still remained unknown. As a contribution to solve these problems, Taguchi method has been proposed in this research as an optimization tool to study the existing interaction between the parameters while at the same time providing the best combination of all parameters levels to improve the AAO-DNA biosensor sensitivity at its optimum performance. Meantime, ANOVA analysis has been proposed to obtain the most influential anodizing parameter to the sensitivity of AAO-DNA biosensor. Prior to optimization, correlation study between the pores‘ dimension and resistance charge transfer (Rct) that affects the sensitivity of AAO-DNA biosensor has been conducted. For this research, AAO thin film-DNA biosensor electrode was synthesized using a single step anodization method in oxalic acid. FESEM was used to observe the AAO surface, while EIS was utilised to study the electrochemical system for DNA hybridization detection. From the first finding, sensitivity of AAO-DNA biosensor was found to be influenced by the ratio of AAO thickness to the pore size. Rct remained under 100 kΩ as long as the ratio of AAO thickness to the pore size was maintained in the range between 1:11 to 1:16. Exceeding the ratio of more than 1:25 will result to the sudden increased in Rct and hence affecting the sensitivity to be reduced. From the second finding, optimization through Taguchi method is the main novelty of this research. The optimum combinations of anodizing parameters were found at 40 V, 17 °C, 0.3 M of oxalic acid at 1 hour. A repetition in experiment was conducted to confirm the efficiency of Taguchi where the sensitivity of the optimized AAO-DNA biosensor electrode was successfully improved to 62.57 % at 0.278 kΩ/M (LOD at 6.497 x 10-15 M) compared to the nominal. From the third finding through ANOVA analysis, the sequences of the most influential anodizing parameter to the AAO-DNA biosensor sensitivity are following the order: anodizing voltage (34.13%) > anodizing time (29.85%) > temperature (20.27%) > electrolyte concentration (15.74%). At the end of this research, optimization of the synthesis of AAO thin film electrode by Taguchi method for DNA sensing was successfully achieved. Since this research had used nonspecific type of DNA target analytes for prototyping development purposed, therefore, it is targeted that this optimized and sensitivity improved AAO thin film electrode will have greater chance to be used widely in the future for detecting various types of DNA, such as dengue, E-coli, or salmonella. Besides, it is of great hope that the outcome from this research may help other researchers to synthesize AAO thin film at its optimum anodizing condition as to improve the sensitivity of the AAO-DNA biosensor