Search

Agricultural settings present unique challenges for the transmission of huge amounts of images over long-range wireless networks. It is challenging to remotely gather data for transmission over a wireless network in research areas due to a lack of basic amenities like internet connections, especially in distant agricultural areas. In this research, the Fast Fourier Transform (FFT) method was used in conjunction with the Discrete Cosine Transform (DCT) method of image compression to achieve a higher compression ratio. In order for a Wireless Sensor Network (WSN) to provide compressed image data to a wireless based station, a LoRaWAN network has been identified. Low-power LoRaWAN networks may regularly transmit compressed images from an agricultural region to a monitoring system up to 15 km away. Images of golden apple snails were collected for this study from a variety of sources. The procedure was coded in MATLAB so that it could be run with input images being judged by the created algorithm. The input images can be compressed with a range of compression ratios (CR) from 3.00 to 50.00, as shown by the simulation results. Compressed image quality is measured not only by the above-mentioned criteria, but also by Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR). According to the numbers, the best achievable compression ratio is 49.04, with an MSE of 172.72 and a PSNR of 25.75 at its highest. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper reported on performance assessment of a field-effect transistor-based biosensor with different widths of the silicon nanowire transducer channel. Silvaco ATLAS device simulation software was used to model the device design with three different channel widths, which are 100, 150, and 200 nm. In this simulation, the bounded target biomolecules during actual detection using the biosensor were represented by several negative interface charge density values applied on the surface of the transducer channel. Increase in accumulation of hole carriers beneath the channel's surface was observed due to the availability of negative interface charges on the surface, hence increased the output drain current. Furthermore, width reduction of the device's channel had allowed more significant change in drain current due to application of different interface charge density values and increased the device's sensitivity. Among the simulated devices, silicon nanowire field-effect transistor-based biosensor with transducer channel width of 100 nm had shown highest sensitivity (-56.45 nA/e−cm2) with lowest interface charge density detection (2.79×1010e/cm-2), which means it enhances the interface charge detection by providing better response and allows lower limit of detection. Therefore, in actual detection, possibility for reaction of the transducer channel to the specific target biomolecule can be increased. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Dengue fever (DF) is one of the deadliest diseases threatening human life. It is transmitted to human body from the bite of female Aedes mosquitoes affected by dengue viruses (DENV). To date, there is no specific antibiotic, vaccine or medication to fight against DENV, hence those infected with DF are often dependent on the non-specific treatments currently available to treat DF symptoms. In these regards, the need for appropriate excellent devices for early detection of DENV could potentially be beneficial, thus a necessary countermeasure can be taken to save human life. We report herein the electrical responses of DENV using poly-Si nanowire array biosensor device. The poly-Si nanowire array was successfully fubricated using the top-down nanofabrication method starting with the sample preparation of the poly-Si-based wafer. The poly-Si nanowire array was developed by using the conventional lithography process, which includes resist coating, soft bake, exposure, development, hard bake, inductively coupled plasma-reactive ion etching (ICP-RIE), and followed by the deposition of the metal contact pads. The surface functionalization of poly-Si nanowire array involves three step procedures, which are surface modification, immobilization, and hybridization in order to detect a specific target of DENV. The morphology and topography of poly-Si nanowires array were observed for the optical characterizations. The electrical characterization based on the current-voltage (I-V) measurement of poly-Si nanowire biosensors was carrier out to analyze the performance of the biosensor in term of limit of detection (LOD). In this research, the poly-Si nanowire array biosensors exhibited excellent performance with LOD of 10 fM, enables for direct deoxyribonucleic acid (DNA) molecules detection. Thus, this poly-Si nanowire array can be utilized as an enhanced transducer and acts as biosensor for future biomedical applications. [ABSTRACT FROM AUTHOR]

Influenza virus is an infectious cause influenza disease. It was understood that the classification of the influenza virus is based on their host-origin and nomenclatures, were coined based on surfuce protein (Hemagglutinin and Neurarninidase). The objective of this work is to make a view on Influenza A viral subtypes. Analysis on conserved and non-conserved regions of neurarninidase from five human influenza A virus sub-types and also analysis of the phylogenetic tree will be included. [ABSTRACT FROM AUTHOR]

The oligonucleotide sequences of four different serotypes of dengue virus that can infect humans, which are DENV-1, DENV-2, DENV -3 and DENV-4 compared and analyzed. Software Clustalx, Genedoc and Splits tree are used to study the origin and the relationship among similar sequences. The information is valuable to design biosensor for dengue viral detection and to help in identification of the dengue virus serotypes in faster, efficient and more affordable for the people affected by dengue in rural areas. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of different doping concentrations on the performance of a polycrystalline silicon nanowire (poly-SiNW) field-effect transistor (FET) for biosensing application. The p-type poly-SiNW FET biosensor was designed and simulated in a commercial numerical simulation, Silvaco ATLAS. Three different p-type doping concentrations (i.e. 0.5x1018, 1x1018, and 5x1018 cm-3) were applied to the channel of the designed biosensor in order to observe their substantial impact on the device electrical characteristic through the simulation process. The doping concentration was indirectly proportional to the electrical resistivity, p of the poly-SiNW channel. Therefore, the reduction of doping concentration had caused the nanowire to exhibit higher electrical resistance, R. Furthermore, the biosensor performance during detection was investigated through the application of several negatively interface charge densities, QF (i.e. -0.1x1012, -0.5x1012, and -1x1012 cm-2) on the surface of the poly-SiNW channel, to imitate the availability of negatively charged target deoxyribonucleic acid (DNAs) captured on the surface of the biosensor. The increase of negatively QF on the channel region of the poly-SiNW had caused accumulation of hole conduction channel beneath the poly-SiNW surface, hence allowed more drain current, ID to flow from drain to source region. The changes in ID values due to the applied QF that represent the different concentrations of captured target DNA by the biosensor were used to calculate the sensitivity and limit of detection (LOD) for the biosensor. Poly-SiNW biosensor with low doping concentration of 0.5x 1018 cm-3 had demonstrated higher sensitivity of 0.29 μA/cm-2 with low LOD down to 8.28x 1010 cm-2, and therefore can be considered to be utilized in the actual fabrication of the poly-SiNW FET biosensor. [ABSTRACT FROM AUTHOR]

Previous study show the preparation, characterization and physical properties of carbon nanotube (CNT) and chitosan (CS). Multi-Wall CNT (MWCNT) and chitosan is utilized on the silicon surface in this studies. Functionalized of Multi Wall Carbon Nanotubes (MWCNTs) were demonstrated using the nitric acid (HNO3) oxidation technique to remove impurities. In this studies, the interaction between CS-MWCNT was investigated and explained according to the UV-VIS result. The range of the wavelength obtained from the UV-Vis data is 200-700nm. The hybrid form of CS-MWCNT proves to be more promising as a surface for biosensing application. [ABSTRACT FROM AUTHOR]

The affectability and unwavering quality of PCR for indicative and research purposes require effective fair systems of extraction and sanitization of nucleic acids. One of the real impediments of PCR-based tests is the hindrance of the enhancement procedure by substances exhibit in clinical examples. This examination considers distinctive techniques for extraction and cleaning of viral DNA from serum tests in view of recuperation productivity as far as yield of DNA and rate recouped immaculateness of removed DNA, and rate of restraint. The best extraction strategies were the phenol/chloroform strategy and the silica gel extraction methodology for serum tests, individually. Considering DNA immaculateness, extraction technique by utilizing the phenol/chloroform strategy delivered the most tasteful results in serum tests contrasted with the silica gel, separately. The nearness of inhibitors was overcome by all DNA extraction strategies in serum tests, as confirm by semiquantitative PCR enhancement. [ABSTRACT FROM AUTHOR]

This paper presents the development of sensor in ultrasensitive detection of formaldehyde gas. The chemical compound, tin dioxide (SnO2) thin film is deposited onto glass insulator. Next, the resistance and voltage of the sensing layer on the interdigitated electrodes (IDE) sensor's substrate is measured. The resistivity of sensor is changed by heat the sensing layer to 150 °C, 175 °C and 200 °C. When formaldehyde gas is supplied inside the test chamber, absorption process occurred at the surface of the heated SnO2 sensing layer. The experimental results show the sensor is capable of high sensitivity sensing of formaldehyde gas at 200 °C, repeatability, and capability detection as low as 11 ppm which produced 0.8 V on electronic reader. Characterization of surface morphological, temperature effect and electrical properties are demonstrated by various measurements. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication process of the zinc oxide thin films for using to act as pH detection by using different PH solution. Sol-gel solution technique is used for preparing zinc oxide seed solution, followed by metal oxide deposition process by using spin coater on the silicon dioxide. Silicon dioxide layer is grown on the silicon wafer, then, ZnO seed solution is deposited on the silicon layer, baked, and annealing process carried on to undergo the characterization of its surface morphology, structural and crystalline phase. Electrical characterization is showed by using PH 4, 7, and 10 is dropped on the surface of the die, in addition, APTES solution is used as linker and also as a references of the electrical characterization. [ABSTRACT FROM AUTHOR]

Human Papillomaviruses (HPV) is the major cause of cervical cancer. HPV 16 and HPV 18 are the two types of HPV are the most HPV-associated cancers and responsible as a high-risk HPV. Cervical cancer took about 70 percent of all cases due to HPV infections. Cervical cancer mostly growth on a woman's cervix and its was developed slowly as cancer. TiO2 particles give better performance and low cost of the biosensor. The used of 3-aminopropyl triethoxysilane (APTES) will be more efficient for DNA nanochip. APTES used as absorption reaction to immobilize organic biomolecules on the inorganic surface. Furthermore, APTES provide better functionalization of the adsorption mechanism on IDE. The surface functionalized for immobilizing the DNA, which is the combination of the DNA probe and the HPV target produces high sensitivity and speed detection of the IDE. The Current-Voltage (IV) characteristic proved the sensitivity of the DNA nanochip increase as the concentration varied from 0% concentration to 24% of APTES concentration. [ABSTRACT FROM AUTHOR]

HPV that also called Human Papillomaviruses is the major cause of the cervical cancer. HPV 16 and HPV 18 are the two types of HPV are the most HPV-associated cancers and responsible as a high-risk HPV. Cervical cancer taken about 70 percent of all cases due HPV infections. Cervical malignancy for the most part development on a lady's cervix and its was developed slowly as cancer disease. TiO2 particles give better performance and low cost of the biosensor. The used of 3-aminopropyl triethoxysilane (APTES) will be more efficient for DNA nanochip. APTES used as absorption reaction to immobilize organic biomolecules on the inorganic surface. Besides, APTES give better functionalization of the adsorption mechanism on IDE. The surface functionalized for immobilizing the DNA, which is the combination of the DNA probe and the HPV target produce high sensitivity andfast detection of the IDE. The Current-Voltage (IV) characteristic proved the sensitivity of the DNA nanochip increase as the concentration varied from 0% concentration to 24% of APTES concentration. [ABSTRACT FROM AUTHOR]

In this work, we investigate the optimum etching of titanium dioxide (TiO2) using inductive couple plasma reactive ion etching (ICP-RIE) on our fabricated devices. By using a combination of CF4/O2 gases as plasma etchant with ratio of 3:1, three samples of TiO2 thin film were etched with different time duration of 10 s, 15 s and 20 s. The ion bombardment of CF4 gases with plasma enhancement by O2 gas able to break the oxide bond of TiO2 and allow anisotropic etch profile with maximum etch rate of 18.6 nm/s. The sample was characterized by using optical profilometer to determine the depth of etched area and scanning electron microscopy (SEM) for etch profile characterization. [ABSTRACT FROM AUTHOR]

This project discusses the fabrication steps of a biosensor device on silicon-on-insulator (SOI) wafer. Conventional photolithography technique is used to fabricate the device. The gold nanoparticles (GNPs) are then used to enhance the sensitivity of the device. By incorporating the GNPs, it is expected to get higher current compared with the device without GNPs due to better conductivity of gold and higher volume-to-ratio. Hence, with the addition of GNPs, it may boost up the signal and enhance the sensitivity of the device. [ABSTRACT FROM AUTHOR]

The p-i-n diode is one of the earliest semiconductor devices developed for power circuit application. It is formed with the intrinsically doped i.e. i-layer sandwiched between the p-type and n- type layers. In this paper, we focus on the integration of the intrinsic region of silicon p-i-n diode to the current-voltage characteristics. In our structure, ntype refers to the bulk substrate and intrinsic region refers to the epitaxial layer of the silicon substrate. We make a thickness variation in the intrinsic region of p-i-n diode and how it affects diode performance. An additional layer is added on the epitaxial layer during the process to control the diffusion from the bottom of bulk substrate. Result shows that intrinsic layer optimization has successfully enhances the diode device robustness in terms of diode current-voltage characteristics, which reflects better manufacturing yield and improve the final product performance. [ABSTRACT FROM AUTHOR]

This paper presents the preparation method of photolithography chrome mask design used in fabrication process of double spiral interdigitated electrode with back gate biasing based biosensor. By learning the fabrication process flow of the biosensor, the chrome masks are designed through drawing using the AutoCAD software. The overall width and length of the device is optimized at 7.0 mm and 10.0 mm, respectively. Fabrication processes of the biosensor required three chrome masks, which included back gate opening, spiral IDE formation, and passivation area formation. The complete chrome masks design will be sent for chrome mask fabrication and for future use in biosensor fabrication. [ABSTRACT FROM AUTHOR]

In this paper, the sol-gel method is used to prepare nanoparticles titanium dioxide (TiO2) thin films at different annealing temperature. The prepared sol was deposited on the p-SiO2 substrates by spin coating technique under room temperature. The nanoparticles TiO2 solution was synthesized using Ti{OCH(CH3)2}4 as a precursor with an methanol solution at a molar ratio 1:10. The prepared TiO2 sols will further validate through structural, morphological and electrical properties. From the X-ray diffraction (XRD) analysis, as-deposited films was found to be amorphous in nature and tend to transform into tetragonal anatase and rutile phase as the films annealed at 573 and 773 K, respectively. The diversification of the surface roughness was characterized by atomic force microscopy (AFM) indicated the roughness and thickness very dependent on the annealing temperature. The two-point probe electrical resistance and conductance of nanoparticles TiO2 thin films were determined by the DC current-voltage (IV) analysis. From the I-V measurement, the electrical conductance increased as the films annealed at higher temperature. [ABSTRACT FROM AUTHOR]

In this paper, sol-gel method spin coating technique is adopted to prepare nanoparticles titanium dioxide (TiO2) thin films. The prepared TiO2 sol was synthesized using titanium butoxide act as a precursor and subjected to deposited on the p-type silicon oxide (p-SiO2) and glass slide substrates under room temperature. The effect of different alcoholic solvents of methanol and ethanol on the structural, morphological, optical and electrical properties were systematically investigated. The coated TiO2 thin films were annealed in furnace at 773 K for 1 h. The structural properties of the TiO2 films were examined with X-ray Diffraction (XRD). From the XRD analysis, both solvents showing good crystallinity with anatase phase were the predominant structure. Atomic Force Microscopy (AFM) was employed to study the morphological of the thin films. The optical properties were investigated by Ultraviolet-visible (UV-Vis) spectroscopy were found that ethanol as a solvent give a higher optical transmittance if compare to the methanol solvent. The electrical properties of the nanoparticles TiO2 thin films were measured using two-point-probe technique. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) nanoparticles based Interdigitated Device Electrodes (IDEs) Nanobiosensor device was developed for intracellular biochemical detection. Fabrication and characterization of pH sensors using IDE nanocoated with TiO2 was studied in this paper. In this paper, a preliminary assessment of this intracellular sensor with electrical measurement under different pH levels. 3-aminopropyltriethoxysilane (APTES) was used to enhance the sensitivity of titanium dioxide layer as well as able to provide surface modification by undergoing protonation and deprotonation process. Different types of pH solution provide different resistivity and conductivity towards the surface. Base solution has the higher current compared to an acid solution. Amine and oxide functionalized TiO2 based IDE exhibit pH-dependent could be understood in terms of the change in surface charge during protonation and deprotonation. The simple fabrication process, high sensitivity, and fast response of the TiO2 based IDEs facilitate their applications in a wide range of areas. The small size of semiconductor TiO2 based IDE for sensitive, label-free, real time detection of a wide range of biological species could be explored in vivo diagnostics and array-based screening. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) nanoparticles based Interdigitated Device Electrodes (IDEs) Nanobiosensor device was developed for intracellular biochemical detection. Fabrication and characterization of Scanning Electron Microscopy (SEM) using IDE nanocoated with TiO2 was studied in this paper. SEM analysis was carried out at 10 kV acceleration volatege and a 9.8 mA emission current to compare IDE with and without TiO2 on the surface area. The simple fabrication process, high sensitivity, and fast response of the TiO2 based IDEs facilitate their applications in a wide range of areas. The small size of semiconductor TiO2 based IDE for sensitive, label-free, real time detection of a wide range of biological species could be explored in vivo diagnostics and array-based screening. [ABSTRACT FROM AUTHOR]