Nanoscience & Nanotechnology-Asia - Volume 9, Issue 2, 2019

The therapeutic efficacy of perorally administered drug is often concealed by their poor oral bioavailability (BA) and low metabolic stability in the gastrointestinal tract (GIT). Most of the newly discovered drug molecules are of high molecular weight and belong to biopharmaceutical classification system (BCS) – II. Poor aqueous solubility and high membrane permeability characteristics of BCS – II drugs limit BA after oral administration. Recently, lipid-based drug delivery (LBDD) systems have gained much importance due to their ability to improve the solubility and BA of poorly soluble drugs. Oral delivery of drugs incorporated in solid lipid nanoparticles (SLNs) has gained considerable interest since the last two decades. SLNs have advantages above the others, as compared to polymer toxicity which is low, as inexpensive excipients and organic solvents are not used. SLNs offer the possibility to develop new therapeutics due to their unique size-dependent properties. An attempt to incorporate drugs into SLNs offers a new prototype in drug delivery system which can be utilized for drug targeting to specific tissue. This review presents elaborate information of SLNs with their aim, advantages, challenges and limitations, the principle of formulation, routes of administration and their biodistribution. It also describes the gastrointestinal absorption and the factors affecting absorption of SLNs from GIT along with its application.

Background: Laser ablation method has high-yield and pure SWCNHs. On the other hand, arc discharge methods have low-cost production of SWCNHs. However, these techniques have more desirable features, they need special expertness to use high power laser or high current discharge that either of them produces very high temperature. As for the researches, the temperatures of these techniques are higher than 4727°C to vaporize the graphite. So, to become aware of the advantages of SWCNHs, it is necessary to find a new way to synthesize SWCNHs at a lower temperature. In other words, reaction field can be expandable at a moderate temperature. This paper reports a new way to synthesize SWCNHs at an extremely reduced temperature. Methods: According to this study, the role of N2 is the protection of the copper holder supporting the graphite rod by increasing heat transfer from the holder. After the current of 70 A was supplied to the system, the temperature of graphite rod was raised to 1600°C. It is obvious that this temperature is somehow higher than the melting point of palladium, 1555°C, and much lower than graphite melting point, 3497°C. Results: Based on the results, there are transitional precursors simultaneous with the SWCNHs. This composition can be created by distortion of the primary SWCNTs at the higher temperature. Subsequently, each SWCNTs have a tendency to be broken into individual horns. With increasing the concentration of the free horns, bud-like SWCNHs can be produced. Moreover, there are individual horns almost separated from the mass of single wall carbon nanohorns. This structure is not common in SWCNHs synthesized by the usual method such as arc discharge or laser ablation. Through these regular techniques, SWCNHs are synthesized as cumulative particles with diameters about 30-150 nm. Conclusion: A simple heating is needed for SWCNTs transformation to SWCNHs with the presence of palladium as catalyst. The well-thought-out mechanism for this transformation is that SWCNTs were initially changed to highly curled shape, and after that were formed into small independent horns. The other rout to synthesize SWCNHs is the pyrolysis of palm olein at 950°C with the assistance of zinc nitrate and ferrocene. Palm olein was used as a promising, bio-renewable and inexpensive carbon source for the production of carbon nanohorns.

Background: Currently, the use of nano-sorbent for the aqueous heavy metals removal is popular among researchers. Methods: In this study, iron oxide nanoparticles were developed as a promising adsorbent for Cr (VI) removal from its aqueous solution. Simple template surface method based on phosphonated alginate biopolymer was employed for the nanoparticles preparation. Different physical characterization tools such as FT-IR, SEM, TEM, XRD and magnetic properties were applied to investigate the physicochemical character of the developed nanoparticles. Batch experiments were used to study the applicability of iron oxide nanoparticles for Cr (VI) removal from aqueous solutions under different preparation conditions. The effects of initial Cr (VI) concentration, pH, adsorbent dosage, contact time and temperature on the removal process were also optimized. Results indicate that the removal efficiency of Cr (VI) increased from 14.44% to 67.85% with increasing iron oxide nanoparticles dosage from 0.025g to 0.3g. Furthermore, the removal percent rose from 39.11% to 56.04% by increasing the environmental temperature up to 50°C. While it decreased with increasing initial concentration of Cr (VI). Results: The best results of removal were recorded at pH=2. Conclusion: Overall, the obtained results indicate that the developed iron oxide nanoparticles could be effectively used as adsorbents for removal of Cr (VI) from aqueous solutions.

Background: The spectral response of Multiple Quantum Barrier (MQB) nano-scale avalanche photodiodes (APDs) based on Si~3C-SiC material system shows considerable responsivity of the device within a very wide wavelength range which includes some portion of Ultra- Violet (UV) spectrum (200- 90 nm), visible spectrum (390-770 nm), near-infrared (700-1400 nm), short-wavelength infrared (1400-3000 nm) and mid-infrared (3000-4000 nm) wavelengths. It has already been concluded from preceding studies that Si~3C-SiC MQB APDs shows better spectral response and excess noise characteristics as compared to equivalent conventional APDs based on Si. Moreover, the superiority of the illumination through p+-side (ITPS) structure has been observed among two probable optical illumination configurations such as illumination through n+- side (ITNS) and illumination through p+-side (ITPS) structures. Methods: In this paper, the time and frequency responses of Si~3C-SiC MQB APDs have been investigated. A very narrow rectangular pulse of pulse-width of 0.4 ps has been used as the input optical pulse having 850 nm wavelength incident on the p+-side of the MQB APD structures (i.e. ITPS is considered here) and corresponding current responses have been calculated by using a rigorous simulation method developed by the authors; finally the frequency responses of the devices are obtained via the Fourier transform of the corresponding pulse current responses in time domain. Results: The width of the current responses are limited to 4.7 and 3.1 ps in Si nano-APD and Si~3C-SiC MQB (consisting of five quantum barriers) nano-APD respectively for the input optical pulse of width 0.4 ps of 850 nm wavelength. On the other hand, the 3 dB upper cut-off frequencies of the above-mentioned diodes are obtained to be 68.63 and 82.64 GHz respectively. Conclusion: Simulation results show that MQB nano-APDs possess significantly faster time response and wider frequency response as compared to the flat Si nano-APDs under similar operating conditions.

Background: Excess noise characteristics of Multiple Quantum Barrier (MQB) nanoscale avalanche photodiodes (APDs) based on Si~3C-SiC heterostructures have been studied in this part of the paper. The multiplication gain and Excess Noise Factor (ENF) of the MQB APDs have been calculated by varying the number of Quantum Barriers (QBs). Methods: The numerically calculated ENF values of MQB APDs have been compared with the ENF of Si flat conventional APDs of similar dimensions and it is observed that the use of QBs leads to significant reduction in ENF of the APDs under similar biasing and illumination conditions. Results: The enhanced ratio of hole to electron ionization rates in MQB structures as compared to the bulk Si APD structure has been found to be the primary cause of improvement in the noise performance of the MQB nano-APDs. Conclusion: Finally, the numerically calculated ENF of Si flat APD has been compared with the experimentally measured ENF of a commercially available Si APD and those are found to be in good agreement; this comparison validates the simulation methodology adopted by the authors in this paper.

Background: The time and frequency responses of Multiple Quantum Barrier (MQB) nano-scale Avalanche Photodiodes (APDs) based on Si~3C-SiC material system have been investigated in this final part. Methods: A very narrow rectangular pulse of pulse-width of 0.4 ps has been used as the input optical pulse having 850 nm wavelength incidents on the p+-side of the MQB APD structures and corresponding current responses have been calculated by using a simulation method developed by the authors. Results: Finally the frequency responses of the devices are obtained via the Fourier transform of the corresponding pulse current responses in time domain. Conclusion: Simulation results show that MQB nano-APDs possess significantly faster time response and wider frequency response as compared to the flat Si nano-APDs under similar operating conditions.

Background: Development of novel materials represents a new and fast evolving application of research in physics and medicine. The area of nanomaterial research has presented interesting physical and chemical properties that cannot be obtained from their macroscopic counterparts. Objective: This study has attempted to attain well-dispersed nanoparticles by variation of polymer concentration. Methods: In order to obtain the calcium borate nanoparticles, polyvinyl pyrrolidone has been used as a capping agent and the preparation method was performed via simple co-precipitation technique followed by heating treatment. In absence of polymer, the heating process causes un-controlled growth of particles with more flocculation and the nanoplate-shaped particles with mean size of 16.0 x30.0 nm was formed. The introduction of polymer concentration of 1 wt% was conducted to the formation of spherical shaped nanoparticles with sufficiently narrow size distribution and small average size of 5.5 nm and 13.0 nm for the initial precipitation and heating process, respectively. Moreover, the synthesized calcium borate nanoparticles showed good luminescence properties with a simple glow curve dominating at 150°C. Results: This curve was utilized to derive trapping parameters including the activation energy, order of kinetic and frequency factor. Conclusion: The well-dispersed calcium borate nanoparticles have been prepared successfully by introduction of sufficient concentration of polymer.

Background: Irbesartan is an anti-hypertensive BCS class II drug exhibiting poor aqueous solubility, which makes it highly challenging for delivery through the oral route. Based on this fact, a self-microemulsifying drug delivery system (SMEDDS) was designed and characterized for augmenting the aqueous solubility and dissolution rate of irbesartan. Methods: Several blends of oil (Capmul MCM EP), surfactant (Tween 80) and co-surfactant (PEG 600) were screened from the preliminary solubility and pseudo-ternary phase diagram studies. Systematic optimization of the SMEDDS was carried out using 3-factor 3-level Box-Behnken design. Results: The optimized formulation was identified by numerical optimization technique, which revealed faster emulsification time, high percent transmittance and drug content, lower globule size < 100 nm, zeta potential and excellent thermodynamic stability. The optimal formulation unveiled more than 93.3% drug release in vitro within 60 minutes, while the pure drug exhibited only 20% drug release, respectively. Conclusion: Ex vivo permeability and in situ intestinal absorption of drugs was improved nearly 2 to 3- fold by the optimal SMEDDS formulation against the pure drug alone (p < 0.001). Overall, the proposed SMEDDS formulation of irbesartan exhibited a superior biopharmaceutical performance.

Introduction: In this paper, authors present the development of a completely automated system to perform 3D micromanipulation and microassembly tasks. The microassembly workstation consists of a 3 degree-of-freedom (DOF) MM3A® micromanipulator arm attached to a microgripper, two 2 DOF PI® linear micromotion stages, one optical microscope coupled with a CCD image sensor, and two CMOS cameras for coarse vision. Methods: The whole control strategy is subdivided into sequential vision based routines: manipulator detection and coarse alignment, autofocus and fine alignment of microgripper, target object detection, and performing the required assembly tasks. A section comparing various objective functions useful in the autofocusing regime is included. Results: The control system is built entirely in the image frame, eliminating the need for system calibration, hence improving speed of operation. A micromanipulation experiment performing pick-and-place of a micromesh is illustrated. Conclusion: This demonstrates a three-fold reduction in setup and run time for fundamental micromanipulation tasks, as compared to manual operation. Accuracy, repeatability and reliability of the programmed system is analyzed.

Background: In 1936, Polya introduced the concept of a counting polynomial in chemistry. However, the subject established little attention from chemists for some decades even though the spectra of the characteristic polynomial of graphs were considered extensively by numerical means in order to obtain the molecular orbitals of unsaturated hydrocarbons. Counting polynomial is a sequence representation of a topological stuff so that the exponents precise the magnitude of its partitions while the coefficients are correlated to the occurrence of these partitions. Counting polynomials play a vital role in topological description of bipartite structures as well as counts of equidistant and non-equidistant edges in graphs. Omega, Sadhana, PI polynomials are wide examples of counting polynomials. Methods: Mathematical chemistry is a division of abstract chemistry in which we debate and forecast the chemical structure by using mathematical models. Chemical graph theory is a subdivision of mathematical chemistry in which the structure of a chemical compound can be embodied by a labelled graph whose vertices are atoms and edges are covalent bonds between the atoms. We use graph theoretic technique in finding the counting polynomials of TiO2 nanotubes. Let ! be the molecular graph of TiO2. Then (!, !) = !!10!!+8!−2!−2 + (2! +1) !10!!+8!−2! + 2(! + 1)10!!+8!−2 Results: In this paper, the omega, Sadhana and PI counting polynomials are studied. These polynomials are useful in determining the omega, Sadhana and PI topological indices which play an important role in studies of Quantitative structure-activity relationship (QSAR) and Quantitative structure-property relationship (QSPR) which are used to predict the biological activities and properties of chemical compounds. Conclusion: These counting polynomials play an important role in topological description of bipartite structures as well as counts equidistance and non-equidistance edges in graphs. Computing distancecounting polynomial is under investigation.

Background: Foot and mouth disease (FMD) is caused by a virus of the genus Aphthovirus, family Picornaviridae which includes several members of medical importance, Multiple subtypes or antigenic variants within each serotype, which make the vaccine from one serotype does not confer protection against the other serotype. Methods: Green synthesized silver nanoparticles were functionalized with FMDV antigen /antibody. The functionalized silver nanoparticles were characterized by UV -Visible spectrophotometer, Fluorescence Spectrophotometer etc. Immunomodulation study, efficacy and toxicity tests on the final product were carried out. Results: The protein profile after immunoprecipitation with AntiFMD antibody analysed on a 12.5% SDS-PAGE which corresponded to the viral proteins. The western blot analysis confirmed the same pattern. When the infected mice were treated with functionalised silver nanoparticles, all mice were recovered from the disease within 12 hrs. The field trial of these nanoformulations showed 100% recovery of the animals with minimum neutralizing antibody without any other physiological problems. Conclusion: Surface modification of silver nanoparticles can create multifunctional materials with potential applications. Nanoformulations developed by functionalizing whole FMD viral protein /antibody with that of silver nanoparticles, elicite an optimal immuno-protective response and as diagnostic agent against foot and mouth disease causing virus The easy method of preparation of nanoparticle, the flexibility of functionalization techniques, long shelf life without cold chain protection and minimum single low dosage reveals the feasibility of this nanoformulation applications ranging from prophylactic vaccines, diagnostics, therapy for all infections leading to autoimmune diseases.

Background: Microfluidic manipulation (including: pumping, mixing and concentrating effects) is highly challengeable for bioengineering and on-chip analysis applications such as point-of-care immune-detection systems. In this research we propose a configurable electrode structure to form various manipulation effects including pumping, mixing and concentrating processes by applying an Alternate Current (AC) electrokinetically-driven flow. Methods: By applying an inhomogeneous electric field causes temperature rise accompanied by temperature gradients generation inside the microchannel. As a result, an AC electrothermal flow generates inside the channel, which is efficient to generate mixing, pumping and concentrating effects. Results: The proposed system is studied numerically by Finite-Element-Method, Based on the results, a) bulk fluid velocity of 100 μm/s is achieved by exciting the electrodes in pumping mode, b) complete mixing efficiency is observed in mixing mode, c) for antibody-antigen binding process (concentrating mode), the surface reaction increases by the factor of 9 after 5 seconds of sample loading. Results reveal that the system is highly efficient for bio-fluid mediums. Conclusion: AC electrothermal fluid manipulation process was investigated numerically inside a microchannel for biological buffers. Back and forth fluid motions, clockwise/counter-clockwise rotational vortexes and also antibody-antigen linking enhancement were achieved by engineering the specific electrode patterns. The manipulation efficiency improves by increasing both the amplitude of electric potential and the ionic strength of biofluid. As a result, our proposed configurable device is of interest for onchip immunoassays and point-of-care devices.

Background: Even applying thermal pulse has been succeeded to reduce the coercivity through randomization the magnetization in such a way stimulate the magnetic reversion, the efficiency of magnetic switching field consumption in writing process still turns out to be an exciting research field to implement the HAMR technology. One of the remarkable geometric properties of HAMR storage media that can be correlated to the writing field reduction issue is the nano-dot thickness. Furthermore, thermal fluctuation causes the magnetization switching process to be probabilistic. This magnetic switching probability determines the magnitude of the writing field. This paper aims to investigate the impact of changes in media thickness on the magnetization process in particular at high temperatures numerically. Methods: Nano-dot was modeled as a parallelepiped with uniaxial anisotropy which was regarded as a magnetically isolated system where no disturbance field of neighboring nano-dots. Simulation arrangements were implemented to evaluate the two viewpoints in the current heat-assisted magnetic recording, either coercivity, as well as writing field consume. Coercivity was gauged by inducing a magnetic field which linearly increased up to 2 Tesla for 2.5 ns at thermal equilibrium to the surrounding. In evaluating writing field consume, thermal field pulse which just below the Curie temperature was generated while the magnetic field inducing the nano-dot. These schemes investigations were based on the Landau-Lifshift- Gilbert equation which accommodates the fluctuation-dissipation theorem in calculating thermal fluctuation effect. Also, temperature dependent material parameters such as magnetic saturation, magnetic anisotropy, and exchange interaction, were taken into account. Results: At room temperature, the coercive and nucleation fields are highly sensitive to the nano-dot thickness. Under thermal assistance, the writing field for 10 nm and 100 nm of the chosen thicknesses are 0.110 T and 0.125 T respectively. These writing grades are significantly lower than the coercivity of the media. For both thicknesses, zero field magnetization reversal phenomena are observed as indicated by the existences of the switching probabilities at H = 0. Conclusion: This numerical study showed that using the heating assistance close to the Curie point, nanodots with the chosen thicknesses and magnetic parameters were probably to be magnetized even no driven magnetic field. Along with this result, magnetic field induction which required to utterly magnetizing was only in the sub-Tesla - about a tenth of the coercive field. During magnetization processes under thermal assistance, randomization of magnetic moments initiated the switching dynamic before the domain wall was nucleated and propagated to reach a single magnetized domain.

Background: Stimuli-responsive microgels have attracted extensive investigations due to their potential applications in drug delivery, catalysis, and sensor technology. The self-assembled mcirogel films can contain different functional groups (e.g., -COOH, -NH2, -C=ONH2) to interact with specific molecules and ions in water, and their study is becoming increasingly important for developing both absorbent materials and sensor coatings. This paper is aimed to obtain a better understanding of the LbL multilayer formation of microgels and the branched PEI using the mass sensitive QCM. Additionally the influence of the temperature and pH on the formation of the microgel films can be achieved. Methods: The temperature and pH sensitive P(NIPAM-co-AA-co-TMSPMA) microgels were prepared by surfactant-free emulsion polymerization and confirmed by FT-IR, laser particle size analysis, and SEM. The obtained microgel and PEI were further used to prepare multilayer thin films by the LbL self-assembly technique monitored by QCM, and their morphology and hydrophilic properties were determined by AFM and water contact angle measurements. Results: The thermosensitive and pH sensitive P(NIPAM-co-AA-co-TMSPMA) microgels were prepared by surfactant-free emulsion polymerization. The size and swelling properties of the microgels prepared are highly dependent on the preparation conditions such as the AA and crosslinker content, and microgels showed good temperature and pH responsive properties. SEM images showed that microgels dispersed evenly on the substrate and had a uniform particle size distribution, which was consistent with the light particle size analysis results. Furthermore, multilayer films composed of the negatively charged microgels and the positively charged PEI have been built up by a facile LbL assembly method and the influence of the deposition conditions on their formation was monitored in real time by QCM. Compared to the temperature of 25 °C, the high temperature of 35°C above the phase transition temperature leads to the more adsorbed mass of microgels on the gold surface of QCM sensors. The absorbed mass values at the deposition pH 7 and 10 are 9.82 and 7.28 μg cm-2, respectively, which are much higher than 1.51 μg cm-2 of the layers deposited at pH 4. The water contact angle and AFM both confirmed the wettability properties and morphology of multilayers on the gold surface of QCM sensors. Conclusion: The formation of the multilayer films on the gold surface by the layer-by-layer deposition technique of the negatively charged microgels and the oppositely charged PEI can be achieved. The controllable multilayer formation can be attributed to the size difference, changes in the hydrophilic property and surface charge density of microgels responsive to the external temperature and pH.

Background: Due to unique chemical and physical properties and potential application in many fields, nanostructured materials have attracted many attentions. Cadmium sulfide (CdS) is a semiconductor that has a wide band gap of 2.42 eV at room temperature and can be served in solar cells and photoluminescence devices. Cadmium sulfide (CdS) is a kind of attractive semiconductor material, and it is now widely used for optoelectronic applications. CdS nano and microstructures can be synthesized via different chemical methods such as microwave-solvothermal synthesis, surfactant-ligand coassisting solvothermal method and hydrothermal route. Also different morphologies of this semiconductor such as dendrites, nanorods, sphere-like, flakes, nanowires, flower-like shape triangular and hexagonal plates, were synthesized. Methods: To synthesis of the nanocomposite, a simple co-precipitation method was served. In briefly, 0.1 g of Pb(NO3)2 was dissolved in the distilled water (Solution 1). Also different aqueous solutions were made from dissolving different mole ratio of Cd(NO3)2.6H2O respect to the lead source in the water (Solution 2). Two solutions were mixed together under vigorous stirring and then S2- solution (0.02 g thiourea in the water) was added to the Pb2+/Cd2+ solution. After that 0.1 g of CTAB as surfactant was added to the final solution. Finally to the synthesis of both sulfide and oxide nanostructures, NaOH solution was added to the prepared solution to obtain pH= 10. Distilled water and absolute ethanol were used to wash the obtained precipitate and then it dried at 80 °C for 8 h. Results: From the XRD pattern it was found that the peaks placed at 24.9°, 27°, 44.1°, 48°, 52°, 54°, 57.8°, 66.8°, 71.2° are associated to CdS compound with hexagonal phase (JCPDS=00-001-0780) that belong to (100), (002), (110), (103), (112), (201), (202), (203), (211) Miller indices respectively. The Other peaks belong to PbS with hexagonal phase (JCPDS=01-078-1897), and CdO with cubic phase (JCPDS=00-001-1049). From SEM images, it was found by choosing the mole ratio to 1:1, very small and uniform particles were achieved. By increasing Pb2+/Cd2+ mole ratio to 1:2, very tiny particles aggregated together were achieved. Conclusion: The results showed that the product can adsorb extra 80% of heavy metal ions from the water. So it can be said that the nanocomposite can be used in the water treatment due to its high photocatalytic and surface adsorption activities. In other words, it can remove heavy metals from the water and also decompose organic pollutions.

Background: The study area is located in the Hebei province Luanxian section along the Luanhe River. The right of Luanhe River is arranged with 3 monitoring sections and is laid with 5 wells in the A-A section and B-B section and 1 well on the floodplain (inside the dike), the distance from the river level is about 10m. The distance between the 4 wells outside the dike is 20m, 50m, 200m and 1500m respectively. 2 wells are arranged on the C-C section, so there are 13 observation wells in the study area. 3# wells and 11# wells have used existing monitoring wells, so 11 wells have been set up actually. The monitoring wells are designed to monitor groundwater level, groundwater quality and isotope analysis. Methods: In the upstream of Luanhe’s A-A section of the No. 4 well near the edge of the woods and downstream of the B-B section of the No. 8 well near the edge of farmland (wheat), each point of soil is sampled to determine the content of nitrate nitrogen and 15N isotope ratio in soil profile. The depth of soil is sampled from surface to groundwater level, the total depth is about 2.5m. Taking about 1kg soil samples at 20cm every time from the ground surface and collect and seal in plastic bags and number. The sampling time was November 2015, March 2016, May 2016 and July 2016, taking 4 times. Results: The analysis showed that higher nitrate content in soil is within 0-60cm, and is same as the depth of fertilizing the crops (including animal manure), so when estimating the proportion of groundwater in nitrate, nitrate content in 0-60cm is assumed as the initial value; which is close to the underground water level in the soil and is regarded as the final value of 60cm, that is, the final value of nitrate into the groundwater, which can estimate the soil nitrate into groundwater ratio. Conclusion: The sources of nitrate in groundwater are complex and related to many factors, such as river water, soil and so on. According to the content of nitrogen and oxygen isotopes, it determines the main source of nitrate nitrogen:soil and Luanhe River. The results showed that the ratio of nitrate to groundwater in the forest soil was 20%~80.8%, and the average value was 56.3%. The proportion of nitrate in the soil in the wheat field was 6.8%~98.2%, with an average value of 48.3%. Nitrate nitrogen from water in proportion of large changes with the seasons, the upper reaches of the Luanhe River (near No. 2 wells) for 0~19.6%; the Luanhe River (near No. 7 wells) for 0~31.5%.

Background: A novel Dual Material Gate Graded Channel and Dual Oxide Thickness Cylindrical Gate (DMG-GC-DOT) MOSFET is presented in this paper. Methods: Analytical model of drain current is developed using a quasi-two-dimensional cylindrical form of the Poisson equation and is expressed as a function of the surface potential, which is calculated using the expressions of the current density. Results: Comparison of the analytical results with 3D numerical simulations using Silvaco Atlas - TCAD software presents a good agreement from subthreshold to strong inversion regime and for different bias voltages. Conclusion: Two oxide thicknesses with different permittivity can effectively improve the subthreshold current of DMG-GC-DOT MOSFET.