Preliminary results of electrical characterization of GO towards MCF7 and MCF10a at different concentrations

GO is the 2D carbon sheet with additional functional groups, is more stable in various solvents, easy to be produced and manipulated especially in biological system. At the moment, GO is only utilized as the drug delivery agent during treatment. In this study, the resistivity of GO towards breast cancer cell (MCF7) and normal breast cell (MCF10a) using interdigitated electrodes (IDE) were investigated. The interaction of different concentrations of GO as the sensing material on the tested cells which act as analyte can change electrical response. The tested cell were treated with six different concentrations of GO and was dropped to the IDE with different period of time in order to examine electrical behavior. For MCF10a, at high concentration the resistances of MCF10 remain in the same order of magnitude with increasing time of detection while for MCF7 at high concentration, the resistances were greatly influenced by the time of detection where the value significantly changed after 5 minutes and 10 minutes. The number of viable cell does not give effect to the resistance

Fluoropolymer as dielectric in organic field effect transistor (OFET)

Fluoropolymer is a type of dielectric material that have been used in fabricating Organic Thin Film Transistor (OTFT). Dielectric layer is one of the layers that make OTFT. It is the layer that sort the electric field that can be used. Fluoropolymer have unique characteristics that can be utilized for fabrication of OTFT. Fluoropolymer is low dielectric contact material which is needed in ultra-large-scale integration (ULSI) to breakdown the parasitic capacitance that affect the value of current flow. Drop cast technique has been used as depositing method on interdigitated electrode (IDE) on glass substrate. The length of the channel is varied to study the IV characteristic. Current- voltage (I-V) measurements have been used to measure the resistance at the different channel length. The value of resistivity can give some impact to the OFET device

Synthetic graphite production of oil palm trunk chip at various heating rate via pyrolisis process

Synthetic graphite was synthesized from oil palm trunk chip in controlled heating condition or pyrolysis process. The heating rate (5 °/min, 10 °/min and 20 °/min) were varied whilst the heating temperature at 800 °C was fixed. After heat treatment process, the samples were characterized by X-Ray Diffraction (XRD) and analyzed using X’Pert Highscore Plus software. Graphite phase was analysed by XRD and it was further supported by RAMAN spectroscopy analysis to confirm the graphitic nature of the synthetic graphite obtained. The morphological study was carried out by using Scanning Electron Microscope (SEM). Based on the analysis, it was confirm that synthetic graphite was successfully synthesized by heat treatment at 800 °C (20 °/min heating rate). Synthetic graphite were observed in the form of amorphous carbon based on the XRD diffraction pattern that match with the reference code of 00-041-1487. RAMAN spectroscopy also showed the formation on D, G and 2D peaks at the respective wavenumber of 1250 cm-1, 1625 cm-1 and 2700 cm-1

paniMmagnetic Film / Helyati Abu Hassan Shaari … [et al.]

Polyaniline (PANi) are of interest conducting polymers due to its ease of synthesis at low cost using simple equipment together with its good conductivity. However, most conducting polymers exhibited poor stability, poor mechanical properties, low thermal conductance, and being amorphous which ultimately affects their performance. Thus, copolymerization of PANi with thermoplastic is one of the methods to retain conductivity of PANi but with extra added properties such as better processability and thermal stability. Therefore, this paper presents the results of the fabrication of a conducting film by copolymerization poly(methyl methacrylate) (PMMA) a thermoplastic polymer, with PANi. In this study, a series of doped PANi with different PANi ratios were copolymerized with PMMA by a free-radical copolymerization reaction to produce a conducting copolymer film. The results from characterization análisis of the film using fourier transform infrared (FTIR) spectrometer, nuclear magnetic resonance (NMR) spectroscopy, and ultraviolet-visible (UV-Vis) spectrometer are presented, which confirmed the chemical structure of both PANi and PMMA in the copolymer. Meanwhile, an evaluation using a resistivity meter found that the prepared copolymer films exhibited conductivity at around 10-7 to 10-6 S/cm, depending on the ratio of PANi incorporated with PMMA. Taking the conductivity properties into account, the electromagnetic interference (EMI) shielding effectiveness of the films has been carried out. In summary, the prepared conducting film can be further exploited to be used as an electronic magnetic shielding material in many electronic applications. The prepared conducting copolymer film for electromagnetic shielding material prepared in this study is known as paniMmagnetic film. The novelty of this research will be in the report of copolymerization PMMA with PANi using the free radical reaction method for electronic magnetic shielding applications

High Speed Low Power CMOS Comparator using Forward Body Bias Technique in 0.13 µm Technology

This paper presents the design of high speed and low power CMOS comparator using a forward body bias technique in 0.13-µm technology. Three types of CMOS comparators’ topologies have been designed in order to compare the performances of speed and power with the conventional comparator. Based on the analysis, the double-tail dynamic comparator is chosen since it shows better performance for high speed and low power. Therefore, a modified high-speed, low power double-tail dynamic comparator is proposed by using a forward body bias technique in order to reduce the supply voltage. The proposed dynamic comparator is implemented in Silterra 0.13-μm CMOS technology with the supply voltage of 1.2 V and sampling frequency of 500 MHz using Cadence EDA tool. The simulation results show that the total power of 152.67 µw with the delay of 72.5 ps is obtained. It can be seen that the proposed dynamic comparator has significantly reduced both the power and delay time compared to the previous design

Revolutionizing cancer treatment by boosting dendritic cell vaccine efficacy with graphene oxide

Dendritic cells (DCs) are potent antigen presenting cells that play a crucial role in stimulating T cell responses against cancer. DC vaccines have been utilized as an immunotherapy approach for cancer treatment, but their effectiveness is hampered by challenges in the tumor microenvironment. Graphene oxide (GO), a cutting-edge carbon-based nanomaterial, has shown promise in modulating DC activation and function. This review highlights the recent advancements in DC vaccines and explores how GO can enhance their efficacy for cancer treatment. By leveraging the unique properties of GO, such as its biocompatibility and immunomodulatory effects, DC vaccines can potentially be optimized to overcome the limitations of the tumor microenvironment and achieve improved outcomes in cancer immunotherapy

Electrical and electromagnetic characteristics of poly (methyl methacrylate)/polyaniline PMMA/PANi conductive film / Helyati Abu Hassan Shaari ... [et al.]

In this study, a conductive film of poly (methyl methacrylate)/polyaniline (PMMA/PANi) was fabricated through a free radical copolymerization reaction using methyl methacrylate (MMA) and aniline monomers at different aniline-to-MMA ratios, namely, 1:1, 1:3, and 1:5. The PMMA/PANi copolymer films exhibited a total electromagnetic interference (EMI) shielding effectiveness (SET) of 0.45, 0.60, and 1.22 dB, respectively, which is more than twice that of the pure PMMA film (0.16 dB). The copolymer films possess the highest conductivity of 2.34 x 10−6 S/cm at the optimum value of aniline for films polymerized with a 1:3 PMMA:PANi ratio. Higher conductivity materials exhibited lower resistance and, thus, absorbed more EM energy, resulting in better EMI shielding

Electrical characterization of GO at different pH towards MCF7 and MCF10a: preliminary result

The intracellular pH of cancerous cell is commonly acidic while the intracellular pH of normal cell is neutral. The objective of this study is to study the electrical characterization in terms of resistance between the pH of sensing material with the intracellular pH of the cells. Three different pH of Graphene Oxide (GO) were used as a solvent to analyze their interaction towards breast cancer cells (MCF7) and breast normal cells (MCF10a). GO which produced by Hummer's method was used due to their solubility and biocompatibility characteristics which easily diffuse through the cell. In this experiment, the characteristics of GO were analyzed and confirmed by using Atomic Force Microscopy (AFM) and Fourier Transform Infrared spectroscopy (FTIR). In order to measure the resistance of MCF7 and MCF10a cells after treated with GO for 24 hours, gold electrodes with 10 μ-gaps of interdigitated electrodes (IDEs) were used. The results were obtained for three periods of time which were immediate, 5 minutes and 10 minutes after the treated cells being exposed at room temperature. The results show that the resistance of MCF10a cells increased after treated with higher pH of GO which is pH 7 and the resistances of the MCF7 cells decreased as the pH of GO increased to pH 7. Finally, the viable cells were calculated by using haemocytometer in order to prove that the increased of the resistances were due to the increased number of viable cells

Microstructure and wettability of Graphene Oxide/TiO2 thin film prepared via sol-gel method

Link to publisher's homepage at https://iopscience.iop.org/The microstructure of graphene oxide TiO2 (GO/TiO2) films on wettability and morphology properties were studied at different amount of Titanium isopropoxide with fixed amount of GO. GO/TiO2 thin films were prepared by using sol-gel method and deposited on glass substrate by spin-coating technique. The formation of GO/TiO2 was confirmed by using Fourier Transform Infrared Spectroscopy (FTIR) study while the morphology of GO/TiO2 was observed by Scanning Electron Microscopy (SEM) analysis. The hydrophilic/hydrophobic interactions of these films were examined by wettability test by measuring the water contact angle of the water drop on the surface of the coating. The wettability tests display that the contact angle of GO/TiO2 was increased from 90.0º to 118.7º after reduce the amount of titanium isopropoxide (TTIP). A small peaks of graphene and Ti were observed in the coated films and more pronounce peaks occur after the films were annealed. However, it was found that the annealing process does not improve the contact angle of the films as compared to the non-annealed films

Graphene geopolymer hybrid: a review on mechanical properties and piezoelectric effect

Link to publisher's homepage at https://iopscience.iop.org/A review on graphene geopolymers hybrid is presented, focusing on the mechanical properties and piezoelectric effect. The method and way of mixing graphene with geopolymers are discussed, including form of graphene that frequently being used by researchers which is graphene oxide (GO) and reduced graphene oxide (rGO). Type of geopolymers being focused in this paper is fly ash and kaolin. The flexural and compressive strength, fracture toughness and stiffness are highlighted in terms of mechanical properties after mixing with geopolymers. The piezoelectric effects on geopolymer is emphasized as graphene acted as conductive filler. Research findings revealed that graphene geopolymer hybrid displayed improvement in mechanical properties despite agglomeration and some defects that need to be rectified. Geopolymers such as metakaolin exhibited piezoelectric effect after being compressed cyclically with the migration of ions and by incorporating graphene nanoplateletes