Adilah Ayoib
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Adilah Ayoib
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Ayoib, Adilah
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Ayoib, Adilah
Ayoib, A.
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Scopus Author ID
57186613000
Researcher ID
GWV-4156-2022

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Screening biosurfactant‐producing actinomycetes: Identification of Streptomyces sp. RP1 as a potent species for bioremediation

2024 , Adilah Ayoib , Subash Chandra Bose Gopinath , Nor Syafirah Zambry , Ahmad Ramli Mohd Yahya

AbstractThis study aimed to isolate biosurfactant‐producing and hydrocarbon‐degrading actinomycetes from different soils using glycerol–asparagine and starch–casein media with an antifungal agent. The glycerol–asparagine agar exhibited the highest number of actinomycetes, with a white, low‐opacity medium supporting pigment production and high growth. Biosurfactant analyses, such as drop collapse, oil displacement, emulsification, tributyrin agar test, and surface tension measurement, were conducted. Out of 25 positive isolates, seven could utilize both olive oil and black oil for biosurfactant production, and only isolate RP1 could produce biosurfactant when grown in constrained conditions with black oil as the sole carbon source and inducer, demonstrating in situ bioremediation potential. Isolate RP1 from oil‐spilled garden soil is Gram‐staining‐positive with a distinct earthy odor, melanin formation, and white filamentous colonies. It has a molecular size of ~621 bp and 100% sequence similarity to many Streptomyces spp. Morphological, biochemical, and 16 S rRNA analysis confirmed it as Streptomyces sp. RP1, showing positive results in all screenings, including high emulsification activity against kerosene (27.2%) and engine oil (95.8%), oil displacement efficiency against crude oil (7.45 cm), and a significant reduction in surface tension (56.7 dynes/cm). Streptomyces sp. RP1 can utilize citrate as a carbon source, tolerate sodium chloride, resist lysozyme, degrade petroleum hydrocarbons, and produce biosurfactant at 37°C in a 15 mL medium culture, indicating great potential for bioremediation and various downstream industrial applications with optimization.

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Coal-vitamin medium for improved scheme of isolating biosurfactant-producing actinomycetes of rare species from soil samples

2023-01-01 , Adilah Ayoib , Subash Chandra Bose Gopinath , Yahya A.R.M. , Zakaria L.

A simplified scheme for the isolation of biosurfactant-producing actinomycetes from soils was developed using different combinations of pretreatments and selective media supplemented with antifungal agent, cycloheximide (0.1 g/l). Pretreatments using hot air-drying techniques as well as soil suspension in phosphate buffer solution (5 mM, pH 7.0) treated with peptone (6%) at 45 °C for 10 min proved to be effectual in decreasing the number of vegetative bacterial cells while preserving many actinomycetes spores. Out of 945 actinomycetes isolates collected from various types of soils, 126 isolates of distinct morphologies were screened for biosurfactant production and 28 isolates were proven positive with 18 from contaminated areas while 10 of the positive isolates were from relatively non-contaminated soils. The combination of coal-vitamin medium, supplemented with antifungal agent, cycloheximide (0.1 g/L), on soil samples treated with peptone (6%) and SDS (0.05%) in 5 mM phosphate buffer, pH 7.0, produced the highest number of actinomycetes isolates recovery. Initial screenings for biosurfactant production using combination of microplate assay, drop collapse method, emulsification activity, and tributyrin agar test were found adequate for copious isolates as these methods also assessed for both low- and high-molecular mass biosurfactant types and worked well for high throughput screening analyses.

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High efficiency carry save adder using modified–gate diffusion input technique

2024-06 , Teoh Yong Keong , Siti Fatimah Abd Rahman , Mohamed Fauzi Packeer Mohamed , Mohamad Faris Mohamad Fathil , Adilah Ayoib , Thikra S. Dhahi

Addition is a fundamental function in the design of a digital system, necessary for applications such as signal processing, arithmetic operations, multiplexers, and control systems. Hence, the digital system’s performance is considerably reliant on the efficiency of the adders. Therefore, designing a 4-bit carry save adder (CSA) that consumes less power, occupies a smaller area, and operates at a higher speed is proposed using the modified–gate diffusion input (MOD–GDI) technique. The primary focus is to reduce the area occupied by decreasing the transistor count as compared with other logic styles (i.e., conventional, and Boolean simplification) for CSA through Cadence Virtuoso simulation based on SilTerra 180 nm technology. Notably, the number of transistors is reduced from 42 in the conventional full adder to 11 in the proposed MOD–GDI design. As a result, the proposed 4-bit CSA with MOD–GDI technique is efficient in improving the speed of addition by reducing the area and power consumption.

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Automated, high-throughput DNA extraction protocol for disposable label free, microfluidics integrating DNA biosensor for oil palm pathogen, Ganoderma boninense

2020-05-01 , Adilah Ayoib , Uda Hashim , Subash Chandra Bose Gopinath

Basal Stem Rot and Upper Stem Rot diseases caused by pathogenic fungus Ganoderma boninense continue to be a major plight in the palm oil industry. Despite continuous research in combating the problem, resolution remains stagnant. Here, developed an automated, high-throughput DNA extraction protocol on microfluidics device for a quick, disposable, label-free detection, within 2 h of assessment. Microfluidics was designed using AutoCAD software, fabricated on microscopic glass substrate using negative photoresist (SU-8 2015) and molded with a biopolymer silicone, Polydimethylsiloxane. G. boninense and unknown pathogenic fungus isolated from rotten mushroom were grown and fractions of extracted DNA were pooled and analyzed for comparison along with synthetic ssDNA of G. boninense. Results from LPM and HPM show successful fabrication with ≤0.1 mm variance between the dimensions in the design before and after lithography process. The PDMS microfluidics show no leakage when run with DNA samples. Analyses from I-V measurement, UV–vis, FTIR, and PCR show comparable results between extracted and synthetic ssDNA of G. boninense and a contrast with the unknown pathogenic fungus, indicating a successful DNA extraction protocol via microfluidics for label-free identification of G. boninense. Optimization of DNA extraction can be further devised for applicability on lab-on-a-chip devices.

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Distinct Detection of Ganoderma Boninense On Metal Oxides-Gold Nanoparticle Composite Deposited Interdigitated Electrode DNA sensor

2021-12-14 , Thivina V. , Uda Hashim , Subash Chandra Bose Gopinath , Adilah Ayoib , Nordin N.K.S. , Muhammad Nur Aiman Uda , Muhammad Nur Afnan Uda

Oil palms suffer severe losses due to Ganoderma boninense infection that causes Basal Stem Rot (BSR). The available detection measuring the severity of BSR disease have not proved satisfactory output. Due to the influence of oil palm industry in country's economy, effective and efficient means of diagnostic measure is mandatory. Among the available diagnostic tools, biosensors were redeemed to yield the most rapid and selective results. To overcome the current issues, herein Interdigitated Electrode (IDE) electrochemical DNA biosensor to detect Ganoderma boninense was successfully designed and fabricated by thermal deposition. Lift-off photolithography fabrication process was applied followed by the surface chemical functionalization via seed deposition. Zinc Oxide (ZnO) and Titanium Dioxide (TiO2) were overlaid and the functionalized metal oxides IDE surfaces were used to detect DNA sequence complementation from Ganoderma boninense. Furthermore, gold nanoparticles were doped to increase the surface to volume ratio and enhance biocompatibility. Characterizations were made by validating the sensor's topology characteristics and electrical characteristics. From the results recorded, it has been justified that IDE with ZnO doped with gold nanoparticles surface serves as an excellent DNA sensor for the detection of Ganoderma boninense with a remarkable current of 290 nA and 176 nA for immobilization and hybridization respectively.

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Impact of Nanogap Thickness on Dielectric-Modulated Field-effect Transistor Biosensor Performance for Uncharged Biomolecules Detection

2023-01-01 , Jasmi M.S. , Mohamad Faris Mohamad Fathil , Mohd Khairuddin Md Arshad , Mohammad Nuzaihan Md Nor , Nur Hamidah Abdul Halim , Rahman S.F.A. , Shaifullah. A. S M. , Adilah Ayoib , Ibrahim M.M.

Uncharged biomolecules sensing performance of dielectric-modulated field-effect transistor (DMFET) biosensor at various nanogap thickness via semiconductor device simulation tool was assessed in this work. The device structures with 10 nm-, 15 nm-, and 20 nm-thick nanogap were constructed for this investigation. Each device structure was applied with dielectric constant ranging from 2 to 7 at the nanogap representing the presence of various biomolecules. These device structures were electrically simulated by supplying gate voltage from 0 V to 2 V and biased with drain voltage of 0.05 V for linear region of operation. Based on the extracted drain current, the reduction of nanogap thickness increase capacitance at the nanogap region. In additional, increase in nanogap's dielectric constant causing an increase of its capacitance, and translated into higher output drain current. Sensitivity calculation and analysis shows DMFET biosensor with 10 nm-thick nanogap demonstrated the highest sensitivity with 6.896 μA/dec, which possibly permit enhanced sensing of uncharged biomolecule.

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Cost-effective fabrication of polydimethylsiloxane (PDMS) microfluidics for point-of-care application

2024-06 , Adilah Ayoib , Noor Amalina Aini Abdul Karim , Uda Hashim , Shahidah Arina Shamsuddin , Siti Fatimah Abd Rahman , Mohamad Faris Mohamad Fathil , Nor Azizah Parmin

Microfluidics fabrication pertains to the construction of small-scale devices and systems that manipulate and control small volumes of fluids. This process involves precise engineering and manufacturing procedures aimed at designing and producing these devices, which find applications in healthcare, environmental monitoring, and chemical analysis. The present study showcases an inexpensive approach to fabricate microfluidics channels using PDMS biopolymer and soft lithography technique to achieve laminar fluid flow. Initially, a robust and adhesive mold was created by fabricating a master template using several layers of SU-8 5 and SU-8 2015 negative photoresists. Subsequently, PDMS microfluidics channels were replicated and sealed onto a glass substrate through plasma bonding treatment. High-power microscopy images and profilometer analyses demonstrated successful fabrication with minimal deviation from the initial designs and the fabricated devices (less than 0.07 mm, less than 0.6°). Both the SU-8 master template and PDMS replicate displayed average microchannel height values and surface roughness of 100 μm and 0.26 μm or lower, respectively. Additionally, the fluid test confirmed laminar flow without any leakage post plasma oxidation, indicating the completion of an efficient and cost-effective fabrication process.

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Publication

Automated, high-throughput DNA extraction protocol for disposable label free, microfluidics integrating DNA biosensor for oil palm pathogen, Ganoderma boninense

2020-05-01 , Adilah Ayoib , Uda Hashim , Subash Chandra Bose Gopinath

Basal Stem Rot and Upper Stem Rot diseases caused by pathogenic fungus Ganoderma boninense continue to be a major plight in the palm oil industry. Despite continuous research in combating the problem, resolution remains stagnant. Here, developed an automated, high-throughput DNA extraction protocol on microfluidics device for a quick, disposable, label-free detection, within 2 h of assessment. Microfluidics was designed using AutoCAD software, fabricated on microscopic glass substrate using negative photoresist (SU-8 2015) and molded with a biopolymer silicone, Polydimethylsiloxane. G. boninense and unknown pathogenic fungus isolated from rotten mushroom were grown and fractions of extracted DNA were pooled and analyzed for comparison along with synthetic ssDNA of G. boninense. Results from LPM and HPM show successful fabrication with ≤0.1 mm variance between the dimensions in the design before and after lithography process. The PDMS microfluidics show no leakage when run with DNA samples. Analyses from I-V measurement, UV–vis, FTIR, and PCR show comparable results between extracted and synthetic ssDNA of G. boninense and a contrast with the unknown pathogenic fungus, indicating a successful DNA extraction protocol via microfluidics for label-free identification of G. boninense. Optimization of DNA extraction can be further devised for applicability on lab-on-a-chip devices.

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Gold-nanoparticle associated deep eutectic solution mediates early bio detection of ovarian cancer

2025-01 , S. Uvambighai Devi , Nor Azizah Parmin , N. Fareezah Jaapar , F. Syakirah Halim , Uda Hashim , Subash Chandra Bose Gopinath , Muhammad Nur Aiman Uda , Voon Chun Hong , Mohammad Nuzaihan Md Nor , Adilah Ayoib , Shahidah Arina Shamsuddin , Norizah Abd Karim

Gold 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.

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Cost-Effective Fabrication of Polydimethylsiloxane (PDMS) Microfluidics for Point-of-Care Application

2024-06-01 , Adilah Ayoib , Karim N.A.A.A. , Uda Hashim , Shahidah Arina Shamsuddin , Abd Rahman S.F. , Mohamad Faris Mohamad Fathil , Nor Azizah Parmin

Microfluidics fabrication pertains to the construction of small-scale devices and systems that manipulate and control small volumes of fluids. This process involves precise engineering and manufacturing procedures aimed at designing and producing these devices, which find applications in healthcare, environmental monitoring, and chemical analysis. The present study showcases an inexpensive approach to fabricate microfluidics channels using PDMS biopolymer and soft lithography technique to achieve laminar fluid flow. Initially, a robust and adhesive mold was created by fabricating a master template using several layers of SU-8 5 and SU-8 2015 negative photoresists. Subsequently, PDMS microfluidics channels were replicated and sealed onto a glass substrate through plasma bonding treatment. High-power microscopy images and profilometer analyses demonstrated successful fabrication with minimal deviation from the initial designs and the fabricated devices (less than 0.07 mm, less than 0.6°). Both the SU-8 master template and PDMS replicate displayed average microchannel height values and surface roughness of 100 μm and 0.26 µm or lower, respectively. Additionally, the fluid test confirmed laminar flow without any leakage post plasma oxidation, indicating the completion of an efficient and cost-effective fabrication process.

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