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Background: Dengue is known as the most severe arboviral infection in the world spread by Aedes aegypti. However, conventional and laboratory-based enzyme-linked immunosorbent assays (ELISA) are the current approaches in detecting dengue virus (DENV), requiring skilled and well-trained personnel to operate. Therefore, the ultrasensitive and label-free technique of the Silicon Nanowire (SiNW) biosensor was chosen for rapid detection of DENV. Methods: In this study, a SiNW field-effect transistor (FET) biosensor integrated with a back-gate of the low-doped p-type Silicon-on-insulator (SOI) wafer was fabricated through conventional photolithography and Inductively Coupled Plasma – Reactive Ion Etching (ICP-RIE) for Dengue Virus type-2 (DENV-2) DNA detection. The morphological characteristics of back-gated SiNW-FET were examined using a field-emission scanning electron microscope supported by the elemental analysis via energy-dispersive X-ray spectroscopy. Results and Discussion: A complementary (target) single-stranded deoxyribonucleic acid (ssDNA) was recognized when the target DNA was hybridized with the probe DNA attached to SiNW surfaces. Based on the slope of the linear regression curve, the back-gated SiNW-FET biosensor demonstrated the sensitivity of 3.3 nAM-1 with a detection limit of 10 fM. Furthermore, the drain and back-gate voltages were also found to influence the SiNW conductance changed. Conclusion: Thus, the results obtained suggest that the back-gated SiNW-FET shows good stability in both biosensing applications and medical diagnosis throughout the conventional photolithography method.

A newly synthesized free fatty acids from waste palm oil functionalized magnetic nanoparticles immobilized on the surface of graphene oxide (FFA@MNP-GO) was successfully synthesized and characterized in this research. The combinations of long alkyl chain of free fatty acid with graphene oxide that consists of large delocalized 77-electron systems and abundant of hydrophilic groups with hydroxyl, epoxide and carboxylic groups offer the determination of simultaneous wide range of polarities of organic pollutants in real matrices through hydrogen bonding, hydrophobic and 77-77 interactions. The fabricated adsorbent was successfully applied as a magnetic solid phase extraction (MSPE) adsorbent for the simultaneous separation of selected phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) in apple and cabbage extracts prior to their high performance liquid chromatography with diode-array detector (HPLC-DAD) determination. Factors affecting the extraction efficiency such as amount of adsorbent, desorption solvent, volume of desorption solvent, extraction time, desorption time, pH and sample volume were investigated and optimized. The results revealed that under optimal conditions, the detection limit of selected PAEs and PAHs were in the range of 0.56-0.97 ng mL-1 and 0.02–0.93 ng mL-1, respectively. The spiked recoveries of real apple and cabbage extracts for PAEs and PAHs were in the range of 81.5-117.6% with good relative standard deviation (RSD) (n = 5) less than 10% and 86.7-118.2% with acceptable RSDs (n = 5) ranging from 1.5 to 11.0%, respectively. This study reported for the first time the use of MSPE procedure for simultaneous determination of chosen PAHs and PAEs in real samples including apple and cabbage extracts by using new adsorbent, FFA@MNP-GO.

A preliminary morphological screening and isolation of bacterial colony from latex industrial wastewater was carried out. Bacteria colonies from latex processing wastewater were isolated from a local latex processing industry. It was found that 17 bacterial isolates had been purified grown on nutrient agar under 35˚C. The colonies were then purified and morphologically indicated via Gram staining and motility test. After morphological observation, it was identified that out of 17 isolates, 9 isolates were Gram positive and 8 isolates were Gram negative. There are 11 out of 17 colonies were rod-shaped bacterial colonies, while the other 6 colonies were cocci-shaped bacteria. There were 11 colonies of gliding bacteria, three colonies were non-motile bacteria and the other three colonies were flagellated bacteria. This study is only limited to morphological observation as the main aim of this study was to investigate the potential occurrence of viable growth in treated latex processing wastewater. The bacterial colonies were classified base on their morphological properties shown. This study has classified several genera such as Staphylococcus, Escherichia, Thiobacillus, Arthrobacter and other Genus. The growth curve of 17 isolates studied and the chemical oxygen demand were determined.

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., 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 importance of nanotechnology in medical applications especially with biomedical sensing devices is undoubted. Several medical diagnostics have been developed by taking the advantage of nanomaterials, especially with electrical biosensors. Biosensors have been predominantly used for the quantification of different clinical biomarkers toward detection, screening, and follow-up the treatment. At present, ovarian cancer is one of the severe complications that cannot be identified until it becomes most dangerous as the advanced stage. Based on the American Cancer Society, 20% of cases involved in the detection of ovarian cancer are diagnosed at an early stage and 80% diagnosed at the later stages. The patient just has a common digestive problem and stomach ache as early symptoms and people used to ignore these symptoms. Micro ribonucleic acid (miRNA) is classified as small non-coding RNAs, their expressions change due to the association of cancer development and progression. This article reviews and discusses on the currently available strategies for the early detection of ovarian cancers using miRNA as a biomarker associated with electrical biosensors. A unique miRNA-based biomarker detections are specially highlighted with biosensor platforms to diagnose ovarian cancer.

Biosensors operating based on electrical methods are being accelerated toward rapid and efficient detection that improve the performance of the device. Continuous study in nano- and material-sciences has led to the inflection with properties of nanomaterials that fit the trend parallel to the biosensor evolution. Advancements in technology that focuses on nano-hybrid are being used to develop biosensors with better detection strategies. In this sense, titanium dioxide (TiO2) nanomaterials have attracted extensive interest in the construction of electrical biosensors. The formation of TiO2 nano-hybrid as an electrical transducing material has revealed good results with high performance. The modification of the sensing portion with a combination (nano-hybrid form) of nanomaterials has produced excellent sensors in terms of stability, reproducibility, and enhanced sensitivity. This review highlights recent research advancements with functional TiO2 nano-hybrid materials, and their victorious story in the construction of electrical biosensors are discussed. Future research directions with commercialization of these devices and their extensive utilizations are also discussed.

A chemical method to synthesize amorphous silica nanoparticles from the incinerated paddy straw has been introduced. The synthesis was conducted through the hydrolysis by alkaline-acidic treatments. As a result, silica particles produced with the sizes were ranging at 60-90 nm, determined by high-resolution microscopy. The crystallinity was confirmed by surface area electron diffraction. Apart from that, chemical and diffraction analyses for both rice straw ash and synthesized silica nanoparticles were conducted by X-ray diffraction and Fourier-transform infrared spectroscopy. The percentage of silica from the incinerated straw was calculated to be 28.3. The prominent surface chemical bonding on the generated silica nanoparticles was with Si-O-Si, stretch of Si-O and symmetric Si-O bonds at peaks of 1090, 471, and 780 cm

In this study, an electrochemical DNA biosensor was developed based on the fabrication of silicon nanowires/platinum nanoparticles (SiNWs/PtNPs) on a screen-printed carbon electrode (SPCE) for the detection of Sus scrofa mitochondrial DNA (mtDNA) in food utilizing a new hybrid indicator, ferrocenylnaphthalene diimide (FND). The morphology and elemental composition of the SiNWs/PtNPs-modified SPCE was analyzed by field emission scanning electron microscopy (FESEM) combined with energy dispersive X-ray spectroscopy (EDX). Cyclic voltammetry (CV) was used to study the electrical contact between the PtNPs and the screen-printed working electrode through SiNWs, while electrochemical impedance spectroscopy (EIS) was used to measure the charge transfer resistance of the modified electrode. The results clearly showed that the SiNWs/PtNPs were successfully coated onto the electrode and the effective surface area for the SiNWs/PtNPs-modified SPCE was increased 16.8 times as compared with that of the bare SPCE. Differential pulse voltammetry used for the detection of porcine DNA with FND as an intercalator confirmed its specific binding to the double-stranded DNA (dsDNA) sequences. The developed biosensor showed a selective response towards complementary target DNA and was able to distinguish non-complementary and mismatched DNA oligonucleotides. The SiNWs/PtNPs-modified SPCE that was fortified with DNA hybridization demonstrated good linearity in the range of 3 × 10−9 M to 3 × 10−5 M (R2 = 0.96) with a detection limit of 2.4 × 10−9 M. A cross-reactivity study against various types of meat and processed food showed good reliability for porcine samples.

The reliability and specificity of the Pap smear rely on the eyewitness to perceive and an assortment of cell variations in clinically obtained cervical specimens. The improvement in early diagnosis to distinguish Human Papillomavirus (HPV) infection has been an issue. ELISA has been intended to analyze the immune response against HPV, and they can be utilized to distinguish the phase of the infection. The objective of this study to characterize the performance of In Vitro Nucleic Acid Hybridization with a correlation with Liquid-Based Cytology and HPV DNA Genotyping Test to assess its use as the potential for the identification of high-risk HPV in cervical clinical specimens. Hybridization utilizing an in vitro nucleic acid DNA-based ELISA method was performed with an improved chemiluminescent for the qualitative and semi-quantitative identification of high-risk HPV in cervical specimens. For analyzing the reliability to identify HPV DNA in cervical Pap smear, we studied the effectiveness of FDA-approved Hybrid Capture II (HCII) utilizing cervical swapping from 20 patient clinical specimens. Two scrapes-outs were positive for the occurrence of HPV. Only specimens displayed positive with HCII test were further confirmed by HPV Genotyping Test. Specimen 2 and 13 were positive for one of the 13 high-risk types in HCII test. Specimen 2 was confirmed by HPV genotyping test as a positive high-risk HPV type 58.

Prognosis of early cancer detection becomes one of the tremendous issues in the medical health system. Medical debates among specialist doctor and researcher in therapeutic approaches became a hot concern for cervix cancer deficiencies early screening, risk factors cross-reaction, portability device, rapid and free labeling system. The electrical biosensing based system showed credibility in higher specificity and selectivity due to hybridization of DNA duplex between analyte target and DNA probes. Electrical DNA sensor for cervix cancer has attracted too many attentions to researcher notification based on high performance, easy to handle, rapid system and possible to miniaturize. This review explores the current progression and future insignificant for HPV E6 genobiosensing for early Detection Strategies of Cervical Cancer.

Arsenic is a major global threat to the ecosystem. Here we describe a highly accurate sensing platform using silica nanoparticles/graphene at the surface of aluminum interdigitated electrodes (Al IDE), able to detect trace amounts of arsenic(III) in rice grain samples. The morphology and electrical properties of fabricated Al IDEs were characterized and standardized using AFM, and SEM with EDX analyses. Micrometer scale Al IDEs were fabricated with silicon, aluminum, and oxygen as primary elements. Validation of the bare Al IDE with electrolyte fouling was performed at different pH levels. The sensing surface was stable with no electrolyte fouling at pH 7. Each chemical modification step was monitored with current–volt measurement. The surface chemical bonds were characterized by fourier transform infrared spectroscopy (FTIR) and revealed different peaks when interacting with arsenic (1600–1000 cm−1). Both silica nanoparticles and graphene presented a sensitive limit of detection as measured by slope calibration curves at 0.0000001 pg/ml, respectively. Further, linear regression was established using ΔI (A) = 3.86 E−09 log (Arsenic concentration) [g/ml] + 8.67 E−08 [A] for silica nanoparticles, whereas for graphene Y = 3.73 E−09 (Arsenic concentration) [g/ml] + 8.52 E−08 on the linear range of 0.0000001 pg/ml to 0.01 pg/ml. The R2 for silica (0.96) and that of graphene (0.94) was close to the maximum (1). Modification with silica nanoparticles was highly stable. The potential use of silica nanoparticles in the detection of arsenic in rice grain extract can be attributed to their size and stability.

The E6 region has higher protuberant probability annealing than consensus probe focusing on another region in the human papillomavirus (HPV) genome in terms of detection and screening method. Here, we designed the first multiple virus single-stranded deoxyribonucleic acid (ssDNA) for multiple detections in an early phase of screening for cervical cancer in the E6 region and became a fundamental evolution of detection electrochemical HPV biosensor. Gene profiling of the virus ssDNA sequences has been carried by high-end bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST), and Clustal OMEGA in a row. The output from bioinformatics tools resulted in 100% of similarities between our virus ssDNA probe and HPV complete genome in the databases. The cross-validation between HPV genome and our designed virus ssDNA provided high specificity and selectivity during screening methods compared with Pap smear. The DNA probe for HPV 18, 5' COOH-GAT CCA GAA GGT ACA GAC GGG GAG GGC ACG 3', while 5'COOH-GGG CGC TGT GCA GTG TGT TGG AGA CCC CGA3' as DNA probe for HPV 58 designed with 66.77% guanine (G) and cytosine (C) content for both. Our virus ssDNA probe for the HPV biosensor promises high sensitivity, specificity, selectivity, repeatability, low fluid consumption, and will be useful in mini-size diagnostic devices for cervical cancer detection.

This paper describes the synthesis of graphene-based activated carbon from carbonaceous rice straw fly ash in an electrical furnace and the subsequent potassium hydroxide extraction. The produced graphene has a proper morphological structure; flakes and a rough surface can be observed. The average size of the graphene was defined as up to 2000 nm and clarification was provided by high-resolution microscopes (FESEM and FETEM). Crystallinity was confirmed by surface area electron diffraction. The chemical bonding from the graphene was clearly observed, with –C=C– and O–H stretching at peaks of 1644 cm(−1) and 3435 cm(−1), respectively. Impurities in the graphene were found using X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The measured size, according to zeta-potential analysis, was 8722.2 ± 25 nm, and the average polydispersity index was 0.576. The stability of the mass reduction was analyzed by a thermogravimetric at 100 °C, with a final reduction of ~ 11%.

This study described a “green chemistry” synthesis of titanium oxide nanoparticle (TiO2-NP) using environment-friendly reducing agents that were from Elodea canadensis. The obtained TiO2-NP has an intense surface plasmon reverberation band at ~ 250 nm with UV–visible spectroscopic investigation which showed the intactness of TiO2-NPs. The morphological behaviour of TiO2-NPs was watched beneath field-emission scanning electron microscopy and transmission electron microscopy, shown that TiO2-NPs have a spherical pattern with a normal estimate of ~ 25 nm in breadth. The occurrence of the critical elements was pinpointed by energy-dispersive X-ray spectroscopy study, which displays the predominant titanium and oxide elements. Further support with a defined morphology and size distribution was rendered by atomic force microscopy and 3D high-power microscopy analyses. X-ray powder diffraction and chosen area electron diffraction examinations affirmed that TiO2-NPs are crystal clear in macrocosm. X-ray photoelectron spectroscopy study was uncovered natural composition of the TiO2-NPs, displaying Ti 2p crested at 458.48 eV with C1s crest for the catalyst that was shaped into a C–H constitute at 284.88 eV. The O 1s spectra moreover were displayed with authoritative vitality at 532.28 eV. XRD analysis gave proportion phase as 75%:25% for anatase and rutile. DLS showed polydispersity index esteem of − 1.23, and zeta potential for green synthesized Ti2O-NPs was − 3.87 mV. A broad hydroxyl peak was identified, and prominent peaks were notified at 1631.78 cm−1 and 3454.51 cm−1 by Fourier-transform infrared spectroscopy analysis.

In the present biomedical field, most of the bioanalytical analyses depend on the electrochemical based systems. Nanomaterials are one of the key factors in enhancing the efficiency of analytical devices. Various nanomaterials such as metal NPs, metal oxide NPs, inorganic NPs, polymeric NPs, carbon-based, and polyoxometalates nanostructures can be seen in a variety of electrochemical analytical systems. Two-electrode, three-electrode, and multi-electrode-based miniaturized electrochemical analytical systems are popular in both research and commercially available systems. Properties of various nanostructures, and their involvement as surface functionalization material for label-free, and label-based ways in different biosensor applications have been discussed. Usage of various analytical methods such as potentiometry, voltammetry, amperometry, conductometry, coulometry, and impedimetric for detection, characterization, and quantification of nanostructure-based sensor systems, have been discussed. Further advantages of nanomaterials in biosensors and other electrodes in electrochemical analytical systems are also discussed. Compared to overall detection methods nanoparticle-based electrochemical analytical systems offer an approach to single molecular detection. By presenting theory to implementation, we hope this chapter provides a broad overview of usage and behavior of nanoparticles in electrochemical analytical systems, which may help readers understand and apply this phenomenon for future electrochemical-based biomedical analytical applications.

Misfolding and accumulation of the protein alpha synuclein in the brain cells characterize Parkinson's disease (PD). Electrochemical based aluminum interdigitated electrodes (ALIDEs) was fabricated by using conventional photolithography method and modified the surfaces with zinc oxide and gold nanorod by using spin coating method for the analysis of PD protein biomarker. The device surface modified with gold nanorod of 25 nm diameter was used. The bare devices and the surface modified devices were characterized by Scanning Electron Microscope, 3D-Profilometer, Atomic Force Microscope and high-power microscope. The above measurement was also performed to measure the interaction of antibody with aggregated alpha-synuclein for normal, aggregated and aggregated alpha synuclein in human serum and distinguished against 3 control proteins (PARK1, DJ-1 and Factor IX). The detection limit for normal alpha synuclein was 1 f. with the sensitivity of 1 f. on a linear regression (R2 = 0.9759). The detection limit for aggregated alpha synuclein was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9797). Also, the detection limit of aggregated alpha synuclein in serum was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9739). These results however indicate that, serum has only minimal amount of alpha synuclein.

SiC nanomaterial (SiCNM) is known for its excellent properties and has great potential for a wide range of applications. In this article, preparation of SiCNMs from different types of graphite was performed by microwave-assisted synthesis. Different types of graphite which are graphite flake (GF) and expanded graphite (EG) were used to react with silica for the synthesis of SiCNMs in laboratory microwave furnace at 1400 °C. It was found that SiC nanowhiskers (SiCNWs) were formed when EG was used, while irregular shaped SiC nanoparticles (SiCNPs) were formed when GF was used. β-SiC appeared as the only phase in the XRD patterns for both SiCNMs formed using GF and EG. SiCNWs and SiCNPs have interplanar spacing of around 0.25 nm which is the axial direction of [111]. The difference of formation mechanism is believed to be the origin of different morphology of SiCNMs synthesized from different types of graphite.

Rice tungro disease is the major disease caused by infection with the rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). In this study, New Zealand White rabbits were immunized with pure viruses for the production of antibodies against both species. The production of polyclonal antibodies against Tungro viral disease using ammonium sulfate precipitation and a protein A affinity column and their assessment are described. Two peaks were found from the protein A affinity column. Peak 1 represents the unbound compounds from the extracted serum and peak 2 represents antibody that bound to protein A, which was eluted using elution buffer. Peak 2 was collected for antibody titration. The amount of pure antibody in the titers was quantified by enzyme-linked immunosorbent assay (ELISA) to capture the tungro viruses. Antibody titer was analyzed by the ELISA method. For anti-RTBV, 1.696 mg/mL was highest at the second bleed and anti-RTSV was 2.3225 mg/mL was highest at the first bleed. These antibodies detected the tungro viral disease well and proved to be a potential probe for the detection of rice tungro disease.

Microfluidic delivers miniaturized fluidic networks for processing liquids in the microliter range. In the recent years, lab-on-chip (LOC) is become a main tool for point-of-care (POC) diagnostic especially in the medical field. In this paper, we presented a design and fabrication on multi disease analysis using single chip via delivery of fluid with the multiple transducers is the pathway of multi-channel microfluidic based LOC’s. 3 in 1 nano biosensor kit was attached with the microfluidic to produce nano-biolab-on-chip (NBLOC). The multi channels microfluidic chip was designed including the micro channels, one inlet, three outlet and sensor contact area. The microfluidic chip was designed to include multiplex detection for pathogen that consists of multiple channels of simultaneous results. The LOC system was designed using Design Spark Mechanical software and PDMS was used as a medium of the microfluidic. The microfluidic mold and PDMS microfluidic morphological properties have been characterized by using low power microscope (LPM), high power microscope (HPM) and surface profiler. The LOC system physical was experimental by dropping food coloring through the inlet and collecting at the sensor contact area outlet.

The aim of this research is to study the morphological analysis of fabricated Interdigitated Electrode (IDE). This device electrode was physically characterized using 3D nano profiler, scanning electrode microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Atomic Force Microscope (AFM). Based on this analysis, IDE pattern was analyzed thoroughly based on the IDE pattern specifications with 5 μM finger gap and this research significantly will stand as a platform quantify the biomolecules in further analysis.

This paper focuses on the ongoing development of real-time monitoring system with implementing the Internet of Things (IoT) element for arsenic heavy metal concentration in paddy field using pH sensor for data collection. The pH sensor will detect the hydrogen ion concentration from the prepared soil put in pot contained with various arsenic concentration. The developed system is then compared with the pH sensor in the market to verify its accuracy and sensitivity. The collected data will be transferred wirelessly into data cloud so that it can store the previous and current reading data. Besides, the system’s function is also to ensure the safeness of paddy plant to be planted with knowing the right amount of arsenic concentration can be passed.

In this article, the effect of heating duration on the synthesis of silicon carbide nanotubes (SiCNTs) was reported. SiCNTs were synthesized from blend of silicon dioxide (SiO2) and multi-walled carbon nanotubes (MWCNTs) in the ratio of 1:3 by using the microwave heating at 1400°C and maintained at duration of 20, 40 and 60 min, respectively. SiCNTs synthesized at heating duration of 40 and 60 min showed the presence of single phase β-SiC in X-ray diffraction patterns. Meanwhile, field emission scanning electron microscope images showed that SiCNTs were formed and no residual of SiO2 and MWCNTs was observed for SiCNTs formed at heating duration of 40 and 60 min. Transmission electron microscopy images showed the SiCNTs have inter-planar spacing of 0.263 nm and tubular structure of nanotube were retained. The peak corresponded to β-SiC was observed at wavelength of 465 nm from the photoluminescence spectroscopy and associated with energy band gap of 2.67 eV. Absorption bands of Si-C bond were detected at 806.23 cm-1 from the Fourier transform infrared spectra. High purity SiCNTs was obtained at 40 and 60 min as indicated by low weight loss by thermo-gravimetric analysis. 40 min is the most suitable heating duration for the synthesis of single phase β-SiCNTs.

A titanium dioxide nanoparticle (TiO2 NP)–mediated resistive biosensor is described for the determination of DNA fragments of Escherichia coli O157:H7 (E. coli O157:H7). The sol-gel method was used to synthesize the TiO2 NP, and microlithography was applied to fabricate the interdigitated sensor electrodes. Conventional E. coli DNA detections are facing difficulties in long-preparation-and-detection-time (more than 3 days). Hence, electronic biosensor was introduced by measuring the current-voltage (I–V) DNA probe without amplification of DNA fragments. The detection scheme is based on the interaction between the electron flow on the sensor and the introduction of negative charges from DNA probe and target DNA. The biosensor has a sensitivity of 1.67 × 1013 Ω/M and a wide analytical range. The limit detection is down to 1 × 10−11 M of DNA. The sensor possesses outstanding repeatability and reproducibility and is cabable to detect DNA within 15 min in a minute-volume sample (1 μL).

According to recent studies, millions of people are suffering from Arsenic (As) toxicity contamination. Arsenic is one of the most toxic and carcinogenic chemical elements and its contamination in paddy field has become a chronic problem. In the agricultural sector, arsenic-contaminated water irrigation has a higher level of arsenic contamination on the top soil, which can affect the quality of crop production such as rice plants. Rice plant requires a considerable amount of water to complete its lifecycle. In Asean countries like Malaysia, Indonesia and Thailand, Arsenic intake from rice is significantly higher, as rice plants have a special ability to take up arsenic from the soil and water used for irrigation. The transfer of arsenic from soil to plant systems is a serious issue that leads to considerable human exposure. Nanotechnology application plays vital role for any field work and research. In this research, the implementation of nanotechnology approach such as silica nanoparticles are able to remove the Arsenic heavy metal contamination. This paper focused on arsenic heavy metal removal using silica nanoparticles analaysed using spectrophotometric method.

Abundant resources of rice straw and carbon-neutral have a lot of potentials to be converted into various value-added product and become more green due to less utilization of chemical usage. Graphene is one of value-added had been converted from rice straw and was successfully synthesized by using activating rice straw ash (RSA) using potassium hydroxide (KOH) at 700 oC with 1:2.5 impregnation ratio. scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), EDX Analysis with a field emission transmission electron Microscope (FETEM) and atomic force microscopy (AFM). The current results can be the model for comparing the synthesize graphene from other plant sources.

Turning waste product into the valuable resources is the best alternative way to overcome the waste management issue. Generally, rice is grown and planted twice a year where a lot of rice by-products have been produced after harvesting the matured paddy. Rice straw is one of turning waste products into the valuable resources and to manage the environmental issues. Generally, rice is grown and planted twice a year where a lot of rice by-products are produced. Rices straw is one of the rice by-products, generated roughly 0.7-1.4 kg per kilograms of harvested milled rice. With the nanotechnological approach, silica particles at nano-size can be produced using the incinerated rice straw. In addition to that, this research will report the synthesis, characterization and adsorption analysis towards the heavy metal removal.

The aim of the research study to design high sensitive biosensor for medical applications. IDE pattern was designed using AutoCAD software with 5 µm ginger gap. The fabrication process was done using a conventional photolithography process and standard CMOS process. The fabricated electrode was physically characterized using a low power microscope (LPM) and a high power microscope (HPM). The electrically validated through I-V measurements and chemically tested with different pH buffer solutions. Al IDE was well fabricated with 0.1 µm tolerance between the design mask and fabricated IDEs. Electrical measurements confirmed that IDE was well fabricated without any shortage and results of similar IDE samples were confirmed that the repeatability of the device. The extremely small current variations in nano ampere range were quantitatively detected using an extra small volume of 2 µl for different pH buffer solutions. It is confirmed that IDEs are sensitive in both alkali and hydroxyl ions medium.

This research was developed to focus on the study of the voltammetric DNA biosensor for the detection of HPV strain 18. In this research, electrical DNA biosensor was expected to detect HPV strain 18 more efficiently by using electrical characterization. In this project, device inspection was conducted to make sure the functional of the gold interdigitated electrode (IDE) by using Scanning Electron Microscope (SEM). 3-Aminopropyl Triethoxysilane (APTES) solution was used for the process of surface modification to form the amine group on the surface of the device to facilitate the attachment of the DNA probe. In this project, synthetic DNA sample and DNA from the saliva of several Biosystems Engineering students were used as the target DNA. The current-voltage (I-V) electrical characterization was conducted to detect the presence of HPV strain 18 in both DNA samples. As the results, perfect alignment between the electrodes on the IDE was detected under SEM. Surface modification of the biosensor successfully conducted which is the covalent bond between APTES and DNA probe increase the electrical. Synthetic DNA shows the presence of HPV strain 18 while there was no HPV strain 18 detected in the DNA from saliva samples.

The aim of this work was to develop a novel, simple, inexpensive, sensitive an electrochemical DNA biosensor based on interdigitated electrodes (IDEs) integrated gold nanoparticle modified electrode by electro less deposition for HPV 18. The biosensor was designed with a 30 mer E6 region of HPV 18 DNA modified probe. The E6 region has been used for their clinical importance properties and suitable as recognition biomarker region. Three different target types were tested which complementary target, non-complementary target and mismatch target. All target were analyzed for detection of HPV 18 in early stages by using Dielectric Analyzer (DA), Alpha-A High-performance Frequency Analyzer, Novocontrol Technologies, Handsagen, Germany associated with the software package Windeta. Complementary target gives a positive result in HPV detection, while non-complementary and mismatch target give negative results. IDE device with 5 nm gap sizes has demonstrated a high performance towards the detection of HPV18 ssDNA target by modified with 30 nm gold nanoparticle. The electrochemical biosensor showed better performance compared to agarose gel electrophoresis assay. This technology can be used as a new and attractive sensor development for detection of virus infection in human bodies.

A novel coronavirus (2019-nCoV) became the seventh member in the family of Coronavirus that infect human. 2019-nCoV became the most severe virus compare to another family of coronavirus. Human airway ephitelial cells have been used to identify and isolate the virus before proceed to reverse trancriptase Polymerase Chain Reaction (RT-PCR). Detailed biological knowledge is crucial for the development of effective countermeasures, diagnostic tests, vaccines and antiviral drugs against the 2019-nCoV. Conserved coding sequences within the spike glycoprotein region of open reading frame in the coronavirus genome was used as the basis to design oligonucleotide probe to detect the virus. Analyses on different strain of coronavirus sequences were done to check the percentage of similarity and consensus region that cause different strain of viruses. The biomarker needed an acceptable length between 22 and 31 mers. The choice of S gene region was identified and can be used as a biomarker probe for biosensor development. It has implications for coronavirus detection techniques in clinical and biosensor diagnostic system.

The agriculture sector plays an important role in economic development in providing rural employment, uplifting rural incomes and ensuring national food security. Harumanis mango has been predominantly produced in the Perlis state of Malaysia, and it is the seasonal once-a-year. However, plant diseases became a serious issue that significantly affects both the quality and quantity of Harumanis mango production. The primary problem with Harumanis mango has experienced by farmers is a disease and the farmers are failed to complete the process of post-harvest for Harumanis mango. Further, in the case of Harumanis mango disease, the symptoms are often detected at the later stage, which makes it difficult to take any further action. Usually, the diseases are controlled by fungicides and the use of synthetic chemicals to eliminate the postharvest diseases and deterioration has their limit due to carcinogenicity, teratogenicity, environmental pollution, effects on food and other side-effects on humans. Up to date, the control of Harumanis mango disease is still challenging, although several studies have been conducted to eradicate and prevent its outbreak in the field. This overview is about Harumanis mango and the prospect in preventing a serious outbreak with Harumanis mango production using interdigitated electrodes (IDE) nano-biosensor.

The persistent infection by high risk HPV is a necessary but not sufficient cause of this cancer which develops over a long period through precursor lesions which can be detected by electrochemical impedance sensor. The HPV driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of women with HPV related cervical disease and these biomarkers can also be used to increase the positive predictive value of current methods. The most influential methods for the detection and identification of HPV using gold nanoparticle (GNP) included electrochemical impedance sensor will visit their sensitivity, selectivity and characteristic detection on synthetic target which are complement of the DNA, non-complement of the DNA and mismatch of the DNA. In difference concentration of synthetic target, which stage can get the exactly value to determine the HPV in strain 16 was evaluated in this research studies.

Bioreceptors can be defined as the basic requirement for specific and sensitive biosensors. The origins of bioreceptors are rooted in biochemistry. The label-free biosensor was developed in response to the demand for a simple, reliable, low cost, rapid, screening method for the early diagnosis of cancer. A range of molecules with biorecognition powers is available naturally, such as antibodies, enzymes, cell receptors, and nucleic acid. Nucleic acid-based biosensors are the preferred choice, compared with immunosensor and enzyme-based sensors, due to their high selectivity and sensitivity. Due to the low-cost of fabrication and stability, nucleic acid biosensors are evolving as reliable and rapid detection tools in medical diagnosis. In this chapter, different transducer platforms are discussed to detect various diseases in clinical diagnosis.

An electrochemical immunosensor based on the screen-printed carbon working electrode with an onboard carbon counter, and silver-silver chloride pseudo-reference electrode for tungro disease, is described in this chapter. A direct competitive enzyme-linked immunosorbent assay format was first developed and optimized on the surface of a carbon screen-printed working electrode by immobilizing the capture antibody (polyclonal) using an electro-deposition of gold nanoparticles conjugated with polyclonal antitetracycline antibodies. The detection reagent, tetracycline-horseradish peroxidase conjugate, was used as an enzyme label. Electrochemical detection was then carried out using 3,3′,5,5′-tetramethylbenzidine dihydrochloride/H2O2 as the enzyme mediator/substrate system, and conducted using chronoamperometry at 300 mV versus an onboard screen-printed Ag-AgCl pseudo-reference electrode. It also showed very high sensitivity using the amplification strategy applied with the use of gold nano-particles. This makes the developed sensor a potential tool for rapid, simple, and sensitive detection of Tungro disease in paddy plantations.

In Malaysia, the first Iodine Deficiency Disorders (IDD) survey was conducted in 1996 and it was discovered that Peninsular Malaysia did not have IDD problem until latter studies showed goitre occurrence of 34.7% in Hulu Langat district and urinary iodine lower than the adequate level of (100-199 ug/L) in Perak and Pahang states (Selamat et al., 2010). Baseline and periodical sampling of children and pregnant woman urine and imported salt commodities for the consumption of the population is mandatory for iodine measurement. Thus, development of quantitative methods of measurement of salt and food iodine is crucial for implementation of the USI program nationwide. In this study, interdigitated electrode (IDE) biosensor, a rapid, sensitive and selective method has been developed to determine the iodine content in both urine and salt. This method includes functionalization and silanization step using 3-aminopropyl triethoxysilane (APTES). The I-V characterization of IDE biosensor was performed using (Keithley 2450), Kickstart software and Probestation. It measures the amount of current flow through IDE which is directly proportional to the concentration of iodine in both urine and salt. Hence, IDE biosensor is proven to be a rapid, selective, sensitive method and can be developed as a new nanotechnology for the elimination of Iodine Deficiency Disorders (IDD) among children and pregnant woman.

Amplification of nano and mircoampere electrical signal to the detectable range is essential in the biosensor field. This research is mainly focused on design an amplifier circuit to capture and amplify three different range of current as nano, micro and mili ampere and convert it to detectable voltage range as an output signal to the processing circuit. The Proteus 8 Pro software was used to design, simulate and calibrate the amplifier circuit. Firstly, current input as mili, micro and nano current were flown through 0.1 mΩ, 10 Ω and 10 KΩ resistors, respectively to convert different current inputs to the similar range in micro voltage. The MAX 4238 opamp IC was used to amplify micro voltage to mili voltage. LM 358 dual operational amplifier was used to supply virtual ground to MAX 4238 amplifier. The amplified output voltage of three different current inputs as nano, micro and mili were nearly equal to theoretical outputs.

Contamination of various food samples became one of the critical issues in food pathogen infection. Food pathogen can be detected by using digital polymerase chain reaction (PCR) and sequencing. These methods were reliable but consuming and take a longer time for detection. The present work describes the innovation to develop a technology to extract double-stranded deoxyribonucleic acid (dsDNA) from food samples and then denatured dsDNA into and single-strand DNA (ssDNA) for further use on the chip using microfluidic device. Microfluidic device is a lab-on-chip device that consist of microfluidic channels that provide paths for biomolecules to flow to individual point of care. DNA extraction is the process by which DNA is separated from proteins, membranes, and other cellular material contained in the cell from which it is recovered. Lysis solution is used in the process of extraction the DNA to break up the cells containing DNA from protein and other cellular materials. This extraction firstly be done in the most labour-intensive in obtaining the DNA biomolecules. Extraction methods may require an overnight incubation, may be a protocol that can be completed in minutes or a couple of hours by using a commercial kit. The disadvantages of the laboratory and commercial kit is due to time-consuming, poor cost-effectiveness, the need to use big laboratory and a complicated process which need an expertise to conduct the experiment and interpret the data. This research is proposed to design and fabricate a microfluidic device that has DNA extraction capabilities. In this research DNA extraction using a commercial kit will be used as a comparison for the quality of the result. The microfluidic device can be used in health care delivery system and will help the doctors in diagnostic process to identify disease of a patient rapidly. Other than that, the output extracted from microfluidic device will be used for DNA probe target interaction for diagnostic kit. The major advantage of microfluidic device is that it consumes less time compared to the conventional chemical methods.

According to media reports in today’s world, millions of people across the globe are suffering from arsenic (As) toxicity. Arsenic heavy metal occurs in different oxidative states in the environment and enters in the food chain through soil and water. In the agricultural field, irrigation with arsenic contaminated water has a higher level of arsenic contamination on the top soil, which may eventually affects the quality of crop production. The major crop like rice requires a considerable amount of water to complete its lifecycle. In Asian countries like Malaysia, Brunei, Indonesia, and Thailand, arsenic intake from rice diet is significantly higher, as rice plants have a special ability to take up arsenic from the soil and water used in irrigation. The transfer of arsenic from soil to plant systems is a serious issue that leads to considerable human exposure in a dangerous way. The applications of nanotechnology play a vital role in many research fields. And therefore, this research, employs the implementation of nanotechnology approach such as silica-grapheme nanocomposite that could be able to minimize the Arsenic heavy metal contamination issues.

A gene sensor for rapid detection of the Human Papillomavirus 16 (HPV 16) which is associated with the appearance of cervical cancer was developed. The assay is based on voltammetric determination of HPV 16 DNA by using interdigitated electrodes modified with titanium dioxide nanoparticles. Titanium dioxide nanoparticles (NPs) were used to modify a semiconductor-based interdigitated electrode (IDE). The surface of the NPs was then functionalized with a commercial 24-mer oligomer DNA probe for HPV 16 that was modified at the 5′ end with a carboxyl group. If the probe interacts with the HPV 16 ssDNA, the current, best measured at a working voltage of 1.0 V, increases. The gene sensor has has a ∼ 0.1 fM limit of detection which is comparable to other sensors. The dielectric voltammetry analysis was carried out from 0 V to 1 V. The electrochemical sensitivity of the IDE is 2.5 × 10−5 μA·μM−1·cm−2.

In this paper, a label-free approach utilizing field-effect transistor (FET) biosensor is presented and demonstrated for deoxyribonucleic acid (DNA) detection related to dengue virus. The biologically active element (in this case for DNA) will have a reaction with a physical transducer (i.e. channel area that connecting the source and drain) and transforms the reaction into a quantifiable signal. This event occurs when an analyte is bound to the recognition element after surface modification, the charge distribution at the surface resulting in current flow across the channel. The field-effect transistor was fabricated using the conventional photolithography approach on thin silicon-on-insulator (SOI) wafer. The source and drain are either doped or undoped (as it initial intrinsic impurity is 1x1015 cm−3). The fabricated device of FET was then observed under scanning electron microscope (SEM), atomic force microscope (AFM), and 3D nano-profilometer to characterize the surface morphology. In addition, the electrical characterization was also performed using Keithley 6487 picoammeter to examine and analyze the bare device. Lastly, the diagnosis of dengue fever is performed by functionalizing the bio-receptor at the channel of the FET which is served as a molecular gate by the binding of a target DNA and monitoring electrical response to the concentrations of dengue virus. The device was tested repeatedly by using different concentrations of DNA target dengue. This step was performed to detect the sensitivity of the device. The device shows a wide-range of detection capability for detection of DNA dengue. The demonstrated results show that the FET has excellent properties for detection of dengue virus with outstanding sensitivity and selectivity properties.

In 1977, there are two scientists, first used the rRNA sequence to study the overall phylogenetic structure of living world, who are Carl Woese and George E. Fox. Herein, based on their foundation, we prepared a set of broad range of 16s rRNA to compare the differences and select the common non-conserved region of the sequence to be used as a probe. We availed complete gene sequences from different species of pathogenic bacteria through the National Center for Biotechnology Information, then align the sequence and performed the comparison and analysis. The identified sequences can be used for the potential biosensing applications.

Human Papillomavirus (HPV) is a standout amongst the most commonly reported over 100 types, among them genotypes 16, 18, 31 and 45 are the high-risk HPV. Herein, we designed the oligonucleotide probe for the detection of predominant HPV type 16 for the sensing applications. Conserved amino acid sequences within E6 region of the open reading frame in the HPV genome was used as the basis to design oligonucleotide probe to detect cervical cancer. Analyses of E6 amino acid sequences from the high-risk HPVs were done to check the percentage of similarity and consensus regions that cause different cancers, including cervical cancer. Basic local alignment search tools (BLAST) have given extra statistical parameters, for example, desire values (E-values) and score bits. The probe, 'GGG GTC GGT GGA CCG GTC GAT GTA' was designed with 66.7% GC content. This oligonucleotide probe is designed with the length of 24 mer, GC percent is between 40 and 70, and the melting point (Tm) is above 50°C. The probe needed an acceptable length between 22 and 31 mer. The choice of region is identified here can be used as a probe, has implications for HPV detection techniques in biosensor especially for clinical determination of cervical cancer.

Silicon carbide is a promising material for various applications, especially for applications in high frequency, high power and high temperature and harsh conditions such as highly oxidative and corrosive environment. Currently, silicon carbide is produced by conventional heating process. For silicon carbide nanomaterials, various methods have been attempted. In this study, SiC nanowhiskers were synthesized by microwave heating of blends of graphite and silica in the ratio of 3: 1. Graphite of two different size, namely micro graphite and nano graphite were used. The blends firstly prepared by ultrasonic mixing graphite and silica in ethanol followed by drying. The blends were then heated by using laboratory microwaves furnace to 1450 °C at heating rate of 20 °C/min for 20 minutes. Finally, the SiC nanowhiskers was characterized by using scanning electron microscope.

One-dimensional silicon carbide nanomaterial (SiCNM) is the leading potential material for high temperature, high power and harsh environment components and devices. This is due to the outstanding properties of the one-dimensional SiCNMs such as high mechanical properties, high hardness, good chemical inertness and excellent electronic properties. In this paper, we reported the successful synthesis of one-dimensional SiCNMs from blend of SiO2 particles with two types of CNTs, namely MWCNTs and SWCNTs by using microwave heating and the effect of types of CNTs on the synthesis of one-dimensional SiCNMs. The result of x-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and thermo-gravimetric analysis revealed that high purity of β-SiC nanotube was obtained from blend of SiO2 particles and MWCNTs while solid SiC nanowire was synthesized from blend of SiO2 particles and SWCNTs and associated with the presence of residual of unreacted SiO2 particles. This clearly shows that types of one dimensional SiCNMs (hollow or solid) can be controlled by using different types of CNTs and thus this study proposed a high efficiency microwave heating method for the synthesis of one-dimensional SiCNMs with controllable morphology.