Now showing 1 - 10 of 33
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Essential semiconductor films in micro-/nano-biosensors: Current scenarios

2021-10-01 , Subash Chandra Bose Gopinath , Ramanathan S. , Mohd Najib Mohd Yasin , Shapiai M.I. , Ismail Z.H. , Subramaniam S.

Background: Engineering nanoscale matter in a controlled functional system has expanded the area of science in the state-of-art of nanotechnology. The urgency in introducing real-time health monitoring sensors and rapid diagnostic tools in medical health is indeed high and crucial to date. The efforts are accompanied by nanotechnology to improve the sensors performances. In this line, semiconductor materials (Silicon/Silica) have been in well-focus to develop micro-/nano-sensors. Methods: Further, additional layering such as metal oxide and graphene material have elevated the current scenario in biosensor developments. Among these, two-dimensional graphene nanomaterial owns its remarkable mechanical, electronic, electrochemical, and optical properties, has excited the medical field to develop graphene-based biosensors for human health diagnosis and monitoring. The oxygen rich graphene materials enhance the bio-functionalization of recognition bio-elements for excellent graphene-based biosensor development. Significance: This review encloses the excellence of semiconductor materials in conjunction with biosensors for monitoring health and diagnosis. The advances and challenges encountered with developing semiconductors for nanobiosensors from laboratory set-up to the novel hand-held device for rapid and accurate human health care are outlined.

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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.

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Facile Electrical DNA Genosensor for Human Papillomavirus (HPV 58) for Early Detection of Cervical Cancer

2023-07-01 , Jaapar F.N. , Nor Azizah Parmin , Halim N.H.A. , Uda Hashim , Subash Chandra Bose Gopinath , Ruslinda A. Rahim , Nadzirah S. , Voon Chun Hong , Muhammad Nur Aiman Uda , Ang W.C. , Zakaria I.I. , Rejali Z. , Afzan A. , Hamzah A.A. , Dee C.F. , Halim F.S.

For decades, a Pap smear test has been applied as a conventional method in detecting Human Papillomavirus caused cervical cancer. False-positive results were also recorded while using it as conventional method. Current biosensor such as Hybrid (II) Capture resulted in higher time consumption and cost. s Meanwhile, in this study we provided facile, mini, rapid, highly sensitive, eco-friendly, and cost-effective sensing system focusing on HPV strain 58 (HPV58) in a nano-size lab-on-chip technology genosensor. 30-mer of virus ssDNA designed and analyzed as a probe via bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST) and ClustalW. Nanotechnology-developed colloidal Gold-nanoparticles (AuNPs) are used in the biosensor fabrication to produce high stability and electron efficient transmission during electrical measurement. AuNPs-APTES modified on active sites of IDEs, followed by immobilization of specific probe ssDNA for HPV 58. Hydrogen binding during hybridization with its target produce electrical signals measured by KEITHLEY 2450 (Source Meter). The genosensor validated with different types of targets such as complimentary, non-complementary and single mismatch oligonucleotides. The serial dilution of target concentration has been experimented triplicate (n=3) range from 1fM to 10µM. The slope of calibration curve resulted 2.389E-0 AM-1 with regression coefficient (R2) = 0.97535.

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Impedimetric transduction from a single-step thin film nanoporous aluminum oxide as a DNA sensing electrode

2024-02-01 , Shamsuddin S.A. , Subash Chandra Bose Gopinath , Mohd Nazree Derman , Jasni I. , Ibau C. , Muhammad Faheem Mohd. Tahir

A two-step anodization process has been widely used to grow a perfectly arranged Anodic Aluminum Oxide (AAO) nanoporous with high regularity and circularity. However, this method requires more time and electricity cost since the second step anodization will be conducted more than a couple of hours up to 24 h to obtain a perfect hexagonally arranged AAO. Besides, the usage of toxic chromic acid to remove the rough surface after the first anodization is not recommended. To solve this issue, a single-step of anodization method to grow AAO at 15 °C in 0.3 M of oxalic acid at 40 V for 1 h has been proposed. In this study, the growth AAO thin film will be tested as a DNA biosensor electrode. Prior to that, instead of using toxic chemicals, couple of drops of phosphoric acid solutions were used to treat the rough, uneven surfaces by promoting hydroxyl groups while at the same time widening and revealed the underneath pores. The AAO thin film is ready for the next step of surface modification without a second anodization step. Surface chemical functionalization using 3-aminopropyl-triethoxysilane (APTES) and glutaraldehyde is performed to immobilize the aminated-ssDNA probe on the surface. The electrochemical impedance technique is employed to monitor the changes in each layer of surface modifications. The charged transfer resistance (Rct) values are linearly increased with each new additional layer on the AAO surfaces during each step of surface modification and with the increase in ssDNA complementary target concentrations (10 fM-10 μM). From the performance test, the single-step AAO thin film electrode has shown great results in functioning as a DNA biosensor through a selectivity test. It has the capability to differentiate the complementary sequences from the single mismatched target with 3-fold.

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Integration of Aluminium Interdigitated Electrodes with Zinc Oxide as Nanocomposite for Selectively Detect Alpha-Synuclein for Parkinson's Disease Diagnosis

2021-12-14 , Adam H. , Subash Chandra Bose Gopinath , Uda Hashim

Parkinson's disease is associated with motor and non-motor symptoms, mostly a motor symptom such as tremor is said to be an early indication for Parkinson's disease development. Because of higher demands for faster and more precise diagnostic methods, it has sparked trends in the development of a biosensor for the diagnosis of Parkinson's disease. Therefore, this study has fabricated a biosensor that is capable of detecting a specific Parkinson's disease biomarker such as aggregation of alpha synuclein and this is crucial in reducing the burden of Parkinson's disease and to be able to detect the disease at the earlier stage. Finding the inconsistent aggregation of alpha-synuclein is a promising method for the early detection of Parkinson's disease. Using conventional photographic process, aluminium interdigitated electrodes (ALIDEs) have been fabricated and employed with sensitive electrochemical strategy for the specific detection of the Parkinson's disease antigen (alpha synuclein). The microelectrode was developed based on aluminium electrode sputtered on silicon substrate. Further, zinc oxide (ZnO) was deposited by sputtering on the working electrode of the ALIDEs using a spin-coating method. The ZnO nanocomposite onto aluminium microelectrode surface provides a favourable platform for efficient loading of antibody via binding with antigen alpha synuclein. The effective loading of the biomolecules (antibody and antigen) on the ZnO nanocomposite surface modified aluminium microelectrode was observed by SEM, AFM and 3D Profilometer. The current flow for each concentration of alpha synuclein was observed at 7.5×10−6 A (10 fM), 8.8×10−6 A (100 fM), and 8.5×10−6 A (1 pM) respectively.

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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.

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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.

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MicroRNA of N-region from SARS-CoV-2: Potential sensing components for biosensor development

2022-08-01 , Halim F.S. , Nor Azizah Parmin , Uda Hashim , Subash Chandra Bose Gopinath , Dahalan F.A. , Zakaria I.I. , Ang W.C. , Jaapar N.F.

An oligonucleotide DNA probe has been developed for the application in the DNA electrochemical biosensor for the early diagnosis of coronavirus disease (COVID-19). Here, the virus microRNA from the N-gene of severe acute respiratory syndrome-2 (SARS-CoV-2) was used for the first time as a specific target for detecting the virus and became a framework for developing the complementary DNA probe. The sequence analysis of the virus microRNA was carried out using bioinformatics tools including basic local alignment search tools, multiple sequence alignment from CLUSTLW, microRNA database (miRbase), microRNA target database, and gene analysis. Cross-validation of distinct strains of coronavirus and human microRNA sequences was completed to validate the percentage of identical and consent regions. The percent identity parameter from the bioinformatics tools revealed the virus microRNAs’ sequence has a 100% match with the genome of SARS-CoV-2 compared with other coronavirus strains, hence improving the selectivity of the complementary DNA probe. The 30 mer with 53.0% GC content of complementary DNA probe 5′ GCC TGA GTT GAG TCA GCA CTG CTC ATG GAT 3′ was designed and could be used as a bioreceptor for the biosensor development in the clinical and environmental diagnosis of COVID-19.

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Greener synthesis of nanostructured iron oxide for medical and sustainable agro-environmental benefits

2022-09-20 , Poh Yan L. , Subash Chandra Bose Gopinath , Subramaniam S. , Chen Y. , Velusamy P. , Chinni S.V. , Gobinath R. , Lebaka V.R.

Nanoscale iron oxide-based nanostructures are among the most apparent metallic nanostructures, having great potential and attracting substantial interest due to their unique superparamagnetic properties. The green production of nanostructures has received abundant attention and been actively explored recently because of their various beneficial applications and properties across different fields. The biosynthesis of the nanostructure using green technology by the manipulation of a wide variety of plant materials has been the focus because it is biocompatible, non-toxic, and does not include any harmful substances. Biological methods using agro-wastes under green synthesis have been found to be simple, environmentally friendly, and cost-effective in generating iron oxide-based nanostructures instead of physical and chemical methods. Polysaccharides and biomolecules in agro-wastes could be utilized as stabilizers and reducing agents for the green production of nanostructured iron oxide towards a wide range of benefits. This review discusses the green production of iron oxide-based nanostructures through a simple and eco-friendly method and its potential applications in medical and sustainable agro-environments. This overview provides different ways to expand the usage of iron oxide nanomaterials in different sectors. Further, provided the options to select an appropriate plant towards the specific applications in agriculture and other sectors with the recommended future directions.

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Advancement in biosensor: “Telediagnosis” and “remote digital imaging”

2022-06-01 , Subash Chandra Bose Gopinath , Ismail Z.H. , Shapiai M.I. , Mohd Najib Mohd Yasin

Current developments in sensors and actuators are heralding a new era to facilitate things to happen effortlessly and efficiently with proper communication. On the other hand, Internet of Things (IoT) has been boomed up with er potential and occupies a wide range of disciplines. This study has choreographed to design of an algorithm and a smart data-processing scheme to implement the obtained data from the sensing system to transmit to the receivers. Technically, it is called “telediagnosis” and “remote digital monitoring,” a revolution in the field of medicine and artificial intelligence. For the proof of concept, an algorithmic approach has been implemented for telediagnosis with one of the degenerative diseases, that is, Parkinson's disease. Using the data acquired from an improved interdigitated electrode, sensing surface was evaluated with the attained sensitivity of 100 fM (n = 3), and the limit of detection was calculated with the linear regression value coefficient. By the designed algorithm and data processing with the assistance of IoT, further validation was performed and attested the coordination. This proven concept can be ideally used with all sensing strategies for immediate telemedicine by end-to-end communications.