Subash Chandra Bose Gopinath
Thumbnail Image
Preferred name
Subash Chandra Bose Gopinath
Official Name
Subash Chandra Bose, Gopinath
Alternative Name
Gopinath, S.
Gopinath, S. C.B
Subash Gopinath, C. B.
Subash, Gopinath
Subash C. B. Gopinath
Main Affiliation
Scopus Author ID
7006558013
Researcher ID
D-2953-2015

Research Output

Filters

51
Reset filters

Settings
Now showing 1 - 10 of 51
  • Publication
    Impact of buried oxide thickness in substrate-gate integrated silicon nanowire field-effect transistor biosensor performance for charge sensing
    ( 2021-07-21)
    Tan Y.M.
    ;
    Mohamad Faris Mohamad Fathil
    ;
    Mohammad Nuzaihan Md Nor
    ;
    Norhayati Sabani
    ;
    Teoh X.Y.
    ;
    Mohd Khairuddin Md Arshad
    ;
    Subash Chandra Bose Gopinath
    ;
    Rahman S.F.A.
    ;
    Uda Hashim
    The paper investigated on performance in charge sensing for substrate-gate integrated silicon nanowire field-effect transistor biosensor at different thickness of the buried oxide layer, sandwiched in between the top-silicon and substrate layers. The device structures with different buried oxide thickness ranging from 100 to 200 nm were designed and simulated using the Silvaco ATLAS device simulation software. The increase of buried oxide thickness reduced the strength of induced electric field that contributes to the formation of inversion layer for current flow through the silicon nanowire channel, hence contributed to the increase in threshold voltage. For simulation of charge sensing, the device demonstrated the ability to identify different interface charge values ranging from -5×1010 to -9×1010 e· cm-2 applied on the surface of the silicon nanowire channel to represent target charge biomolecules that bound to the biosensor in actual detection. Significant change in threshold voltage can be observed due to the applied interface charge density values and was evaluated to determine the sensitivity for charge sensing performance. The device shows better performance when designed with buried oxide thickness of 200 nm at sensitivity of 1.151 V/e· cm-2.
  • Publication
    Natural resources for nanoparticle synthesis
    ( 2020-01-01)
    Letchumanan I.
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    Drastically growing research areas are mainly dependent on nanotechnology for the purpose of a better outcome and to propose new advancements in their respective field. In fact, nanotechnology has been an attraction field for all researchers due to their outstanding key prospects in all the fields. Truly, to claim that nature also can be distinguished as a superior nanotechnologist. Nanoparticles are the subclass of nanotechnology which can be found everywhere and every time. Nanoparticles are particles with nano-sized range which are highly mobile and precise. In nature, nanoparticles can be found in volcanic ash, ocean spray, natural water, soil, plant extract, and plant biomass. Naturally, existing compounds or minerals by the bioreduction process can be either highly toxic or nontoxic to the environment. This chapter generally presents the types of nanoparticles that exist naturally and their way of production.
  • Publication
    Surface charge transduction enhancement on nano-silica and - Alumina integrated planar electrode for hybrid DNA determination
    ( 2021-06-01)
    Ramanathan S.
    ;
    Prabakaran A/L Poopalan
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Anbu P.
    ;
    Lakshmipriya T.
    ;
    Salimi M.N.
    ;
    Pandian K.
    This study represents the surface charge transduction, an efficient and inexpensive biosensor with modifications by silica-alumina entities and determination of gene sequence hybridization. The sensing surface was made by the planar aluminium interdigitated electrode on silicon substrate. Silica and alumina nanoparticles were engineered on the planar transducer surface and the device sensitivity was investigated. The morphology of silica and alumina particles was characterized through the high-resolution election microscopic analyses and revealed the spherical shaped nanoscale sizes at the range of 45–100 nm. The elemental compositions of silica and alumina nanomaterial were affirmed through energy disperse spectroscopy as prominent peaks of Si, Al and O were observed. Selected area electron diffraction analysis of silica and alumina justified their crystalline and amorphous nature, respectively. XRD analysis revealed the expending cristobalite state of silica crystal and γ-alumina for planar electrode surface enhancement. Fourier transform infrared spectroscopy peak observed at 1094 cm−1 revealed the asymmetric stretching of silica nanoparticles whereas the projecting peak observed at 806 cm−1. Additionally, Al–O stretch and Al–O–Al bending modes were justified with the peaks at 585 and 825 cm−1, respectively. Band gap values of silica and alumina computed were 6.75 eV and 3.20 eV, respectively. The results of DNA probe immobilization and complementation have affirmed that silica modified transducer shows the lowest detection at 10 aM whereas alumina modified transducer displayed insignificant current signal and failed to detect DNA hybridization. To investigate the effect of silica entity and its nanocomposite in detecting DNA hybridization, aluminosilicate nanocomposite was deposited on transducer and attained highly sensitive gene detection. Based on the coefficient regression value, aluminosilicate nanocomposite modified planar transducer has shown good device sensitivity (R2 = 0.96) in contrast to silica and alumina entities.
  • Publication
    Nanostructured aluminosilicate from fly ash: Potential approach in waste utilization for industrial and medical applications
    ( 2020-04-20)
    Ramanathan S.
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Prabakaran A/L Poopalan
    Fly ash is found as a significant solid waste released from power plants to the atmosphere, but its qualitative and quantitative consumptions for the sustainability are ambiguous. The main issues aroused with the disposal of fly ash are the requirement of a large land area for landfills, cause toxicity and pollution to the soil and groundwater due to the accumulation of heavy metals. Although fly ash is highly recommended for soil amelioration and cement manufacturing, the ultimate usage of the solid waste causes unsatisfactory effect to the ground system and cementitious product, respectively. Apart from direct utilization and disposal of fly ash, it has been well reported in literature for the synthesis of nanosized particles due to its enrichment in silica, kaolin, iron, and alumina. With this regard, aluminosilicates have been acknowledged as one of the prospective nanocomposites synthesized from fly ash. It has proven that naturally occurring geopolymerization of fly ash under alkaline medium results is in the formation of aluminosilicates. As such, synthetic aluminosilicates were highly encouraged to extract from fly ash in large scale due to their excellent physiochemical properties and applications. This overview intends to fill-up the knowledge gap through critically reviewing about fly ash waste for the synthesis of aluminosilicate nanocomposite. The applications of fly ash derived aluminosilicates in industries such as wastewater treatment, agriculture system and as antioxidants are gleaned. Besides the heavy industrial potential, this review encompasses the prospective alternative consumption of fly ash for the production of nanostructured aluminosilicates and their comprehensive assessment in medical applications, especially in drug carrier and drug delivery systems, bone engineering, biosensors, hemodialysis, and intestinal therapeutics.
  • Publication
    Impedimetric Lectin Biosensor for Prostate Cancer Detection
    ( 2021-01-01)
    Abd Rahman S.F.
    ;
    Mohd Khairuddin Md Arshad
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohamad Faris Mohamad Fathil
    ;
    Sarry F.
    ;
    Md Nor M.N.
    There is considerable attention on the determination of prostate-specific antigen (PSA) glycosylation patterns for the early detection of prostate cancer, as it is one of the most reliable tumor biomarkers. In this study, the highly effective lectin-based biosensor utilizing gold interdigitated microelectrode was developed as a sensing transducer, coupled with electrochemical impedance spectroscopy (EIS) for the sensitive detection of biomolecules event on the device. The self-assembled monolayer using 11-mercaptoundecanoic acid was utilized to modify the sensor surface for the conjugation of Maackia amurensis lectin as biorecognition elements. The analytical analysis of the developed lectin biosensor with PSA glycosylation through impedimetric measurement exhibited a linear detection ranging from 100 pg/mL to 100 ng/mL and attained a detection limit of 27.6 pg/mL.
  • Publication
    Lectin bioreceptor approach in capacitive biosensor for prostate-specific membrane antigen detection in diagnosing prostate cancer
    ( 2021-03-01)
    Subramani I.G.
    ;
    Ramzan Mat Ayub
    ;
    Subash Chandra Bose Gopinath
    ;
    Perumal V.
    ;
    Mohamad Faris Mohamad Fathil
    ;
    Mohd Khairuddin Md Arshad
    This research reports a new approach with lectin-based capacitive non-faradaic biosensor for the detection of prostate-specific membrane antigen (PSMA) as a promising diagnostic marker for determining prostate cancer. PSMA expression is significantly higher in malign hyperplasia, thus can be effectively employed to discriminate other benign prostatic diseases. Herein, the aluminium interdigitated electrode was fabricated and modified by a linker, 2-mercaptoacetate to form the self-assembled monolayer. Gold nanoparticles were used as a signal amplifier and supported the conjugation of Concanavalin A, for efficient capacitive sensing of PSMA. Scanning electron microscope observation effectively captured the surface modification on the aluminium surface by revealing the specific adherence of gold nanoparticles with Concanavalin A. Moreover, the successful surface modification was further validated by atomic force microscopy, Fourier transforms infrared spectroscopy, and X-ray photoelectron spectroscopy. The interaction analysis of Concanavalin A with PSMA by capacitive non-faradaic measurement exhibited a linear detection range from 10 pM to 100 nM and attained the detection limit and sensitivity of 10 pM and 1.65 nF/pM respectively as the comparable performance to the current sensing strategies. Furthermore, the fabrication and quantification of PSMA as demonstrated here are relatively simple and can be employed for the straightforward detection of other biomarkers.
  • Publication
    Aluminosilicate Nanocomposites from Incinerated Chinese Holy Joss Fly Ash: A Potential Nanocarrier for Drug Cargos
    ( 2020-02-25)
    Ramanathan S.
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohd Khairuddin Md Arshad
    ;
    Prabakaran A/L Poopalan
    ;
    Anbu P.
    ;
    Lakshmipriya T.
    An incredible amount of joss fly ash is produced from the burning of Chinese holy joss paper; thus, an excellent method of recycling joss fly ash waste to extract aluminosilicate nanocomposites is explored. The present research aims to introduce a novel method to recycle joss fly ash through a simple and straightforward experimental procedure involving acidic and alkaline treatments. The synthesized aluminosilicate nanocomposite was characterized to justify its structural and physiochemical characteristics. A morphological analysis was performed with field-emission transmission electron microscopy, and scanning electron microscopy revealed the size of the aluminosilicate nanocomposite to be ~25 nm, while also confirming a uniformly spherical-shaped nanostructure. The elemental composition was measured by energy dispersive spectroscopy and revealed the Si to Al ratio to be 13.24 to 7.96, showing the high purity of the extracted nanocomposite. The roughness and particle distribution were analyzed using atomic force microscopy and a zeta analysis. X-ray diffraction patterns showed a synthesis of faceted and cubic aluminosilicate crystals in the nanocomposites. The presence of silica and aluminum was further proven by X-ray photoelectron spectroscopy, and the functional groups were recognized through Fourier transform infrared spectroscopy. The thermal capacity of the nanocomposite was examined by a thermogravimetric analysis. In addition, the research suggested the promising application of aluminosilicate nanocomposites as drug carriers. The above was justified by an enzyme-linked apta-sorbent assay, which claimed that the limit of the aptasensing aluminosilicate-conjugated ampicillin was two-fold higher than that in the absence of the nanocomposite. The drug delivery property was further justified through an antibacterial analysis against Escherichia coli (gram-negative) and Bacillus subtilis (gram-positive).
  • Publication
    Design and simulation of Cylindrical Stacked Silicon Nanowire (SiNW) field-effect transistors
    (IEEE, 2023-12)
    H’ng Chee Chang
    ;
    Mohd Khairuddin Md Arshad
    ;
    Mohamad Faris Mohamad Fathil
    ;
    Mohammad Nuzaihan Md Nor
    ;
    Subash Chandra Bose Gopinath
    ;
    Ramzan Mat Ayub
    In continuous effort to increase the current drive without sacrificing the off current and better off gate control on the channel, the MOSFET devices have advanced from classical, planar, single-gate and three-dimensional devices with multi-gate structures. Recently, multi-bridge-channel technology has become a feasible solution beyond FinFET multi-gate structure. In this work, we design Gate-All-Around (GAA) based on silicon nanowire. Numerical simulation based Silvaco Device tools has been used to design multiple number of cylindrical nanowires, then followed by different channel diameter, consisting of 20, 30 and 40 nm. The devices are the characterized on transconductance, threshold voltage, DIBL and subthreshold slope. The simulation results indicate that the device performance is best at a nanowire diameter of 20 nm due to improved gate control over charge distribution. Regarding the number of nanowires, the voltage performance is not significantly affected by Nnw =1 or higher. However, higher numbers of nanowires, such as Nnw = 3, demonstrate improved drain current and transconductance.
  • Publication
    Immunosensing prostate-specific antigen: Faradaic vs non-Faradaic electrochemical impedance spectroscopy analysis on interdigitated microelectrode device
    ( 2020-11-01)
    Ibau, Conlathan
    ;
    Mohd Khairuddin Md Arshad
    ;
    Mohammad Nuzaihan Md Nor
    ;
    Subash Chandra Bose Gopinath
    ;
    Mohamad Faris Mohamad Fathil
    ;
    Shahidah Arina Shamsuddin
    This work explores Electrochemical Impedance Spectroscopy (EIS) detection for a highly-sensitive quantification of prostate-specific antigen (PSA) in Faradaic (f-EIS) and non-Faradaic modes (nf-EIS). Immobilization of monoclonal antibody specific to PSA (anti-PSA) was performed using 1-ethyl-3-dimethylaminopropylcarbodiimide hydrochloride and N-hydroxysuccinimide crosslinking agents in order to conjugate carboxylic (-COOH) terminated group of 16-Mercaptoundecanoic acid with amine (-NH3+) on anti-PSA epitope. This approach offers simple and efficient approach to form a strong, covalently bound thiol-gold (S–Au) for a reliable SAM layer formation. Studies on the topographic of pristine Au-IDE surface were performed by Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy techniques, meanwhile a 3-dimensional optical surface profiler, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy techniques were used to validate the successful functionalization steps on the sensor transducer surface. Detection of PSA in f-EIS mode was carried out by measuring the response in charge transfer resistance (Rct) and impedance change (Z), meanwhile in nf-EIS mode, the changes in device capacitance was monitored. In f-EIS mode, the sensor reveals a logarithmic detection of PSA in a range of 100 ng/ml down to 0.01 ng/ml in Phosphate Buffered Saline with a recorded sensitivity of 2.412 kΩ/log10 ([PSA] ng/ml) and the limit of detection (LOD) down to 0.01 ng/ml. The nf-EIS detection mode yields a logarithmic detection range of 5000 ng/ml down to 0.5 ng/ml, with a sensitivity of 8.570 nF/log10 ([PSA] ng/ml) and an LOD of 0.5 ng/ml. The developed bio-assay yields great device stability, specificity to PSA and repeatability of detection that would pave its way for the future development into portable lab-on-chip bio-sensing system.
      10  27
  • Publication
    Selective detection of amyloid fibrils by a dipole moment mechanism on dielectrode – Structural insights by in silico analysis
    ( 2023-03-01)
    Adam H.
    ;
    Subash Chandra Bose Gopinath
    ;
    Kumarevel T.
    ;
    Mohd Khairuddin Md Arshad
    ;
    Adam T.
    ;
    Zaliman Sauli
    ;
    Subramaniam S.
    ;
    Uda Hashim
    ;
    Chen Y.
    Amyloid fibrils are associated with different neurodegenerative diseases, a final product of several protein aggregation pathways. Parkinson's disease is a type of amyloidosis, characterized by the accumulation and propagation of amyloid fibrils of alpha-synuclein. The detection of fibrils at low concentrations is critical for the diagnosis of Parkinson's disease. We report a novel technique for the selective detection of amyloid fibrils through a dipole moment on a dielectrode surface. A sensitive dielectrode sensor for detecting aggregation of alpha synuclein and works by interacting an antibody on two-electrode surface functionalized gold interdigitated electrode. For the physical characterization of the sensing surface and finger electrodes, high-power microscope, scanning electron microscope, and 3D-profilormeter were used. Electrical characterization was performed on the sensing surface by using Keithley 6487 picoammeter. Based on the stability analysis with various electrolytes solutions, the sensor was found to be stable from pH 3. Further, under optimal circumstances, a linear range of alpha synuclein fibril detection was from 100 aM to 100 pM [y = 5E-06x + 5E-06; R² = 0.9724], and the limit of detection was estimated to be 100 aM based on S/N = 3. This study was further anchored by molecular docking analysis with synuclein peptide (47−56). We predict that advancements in this direction will assist in clarifying the complex process posed by Parkinson's disease.
      2