Now showing 1 - 4 of 4
  • Publication
    Evaluation of GO and rGO on breast cancer cell line (MCF7) and normal breast cell line (MCF10a) for cell viability and electrical response
    (Universiti Malaysia Perlis (UniMAP), 2018-12)
    Siti S. Mat Isa
    ;
    N. S. Mazlan
    ;
    ;
    L. F. A. Talip
    ;
    Rafeezul Mohamed
    ;
    Graphene based materials become a phenomenal in various applications including biomedical devices due to their excellent properties. Their effects towards certain diseases were broadly studies and presented. However, the work has been performed was only limited to the graphene oxide (GO) and its biocompatibility only. In this work, the interaction of GO and reduced graphene oxide (rGO) on breast cancer cell (MCF7) and normal breast cell (MCF10a) was investigated specifically on the cell viability, cell mortality and current-voltage (IV) relationship. Graphene oxide and rGO at the concentration of 100μg/mL were prepared by chemical methods. The morphology and quality of both materials were characterized using AFM and Raman Spectroscopy. The cells were treated for 24 hours and the effects of these materials on the viability and mortality of the cell were observed. The interaction between graphene-based materials and both cells significantly impact the current-voltage (IV) characteristics. The results show that GO and rGO did not affect the cell viability but only small percentage different was obtained on cell mortality. It also observed that the resistance of cell treated with rGO decreased with time for MCF7 and vice versa for MCF10a. While for GO, the resistance of cell increased with time for MCF7 and vice versa for MCF10a. These clear patterns of these interactions lead to a good input for biosensor fabrication which was aimed to be used as the early diagnosis cancer stem cell point of care (POC) device.
  • Publication
    Elemental analysis of bamboo charcoal from gigantochloa albociliata
    (Universiti Malaysia Perlis (UniMAP), 2018-12)
    Siti S. Mat Isa
    ;
    ; ;
    A. S. Rosman
    Bamboo the most abundant plant in the world has attracted a lot of interests due to their excellent potentials in many ways. The bamboo charcoal itself can be utilized in water purification, electromagnetic wave absorber, blood purification and even dye sensitized solar cell. In Malaysia, elements of bamboo charcoal from Gigantochloa Albociliata have not yet been studied. Properties of bamboo charcoal totally depend on the applied temperature and time during carbonization and activation process. In this paper, elemental analysis of carbonized bamboo charcoal at 500°C and activated bamboo charcoal at 900°C and 1100°C has been performed using Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) after being prepared in two different mediums; DI water and ethanol. The results show that carbonized samples CS64 TK and CS88M show similar trend of peak in both solvents. Some peaks at 3278 cm-1 and 1637 cm-1 which attribute to O-H (stretching) and C-H (stretching) were broader for both samples in DI water compared to ethanol. In ethanol, some bands like 2886 cm-1 (C-H stretching), 1394 cm-1 (C-H bending), 1057 cm-1 (CO-O-CO stretching) and 872 cm-1 (C-H bending) were clearly observed. Similar results were obtained for activated samples; ABC900 and ABC1100. From the XRD analysis, it was confirmed that carbonized and activated bamboo charcoal were amorphous carbon. As the activation temperature increased up to 1100°C, the d0002 spacing decreased while the graphite crystallite size LC(0002) increased.
  • Publication
    rGO-SWCNT hybrid for counter electrode in dye sensitized solar cell
    (Universiti Malaysia Perlis (UniMAP), 2018-12)
    M. R. Muda
    ;
    Siti S. Mat Isa
    ;
    Towards platinum free counter electrode in dye sensitized solar cells, some carbon-based materials like carbon nanotubes and graphene are fully utilized due to their extraordinary properties such as high aspect ratio and conductivity. In this paper, single-walled carbon nanotubes (SWCNT), reduced graphene oxide (rGO) and hybrid structure of rGO-SWCNT spray coated counter electrodes were compared with graphite as the reference material. The morphology of these materials was analyzed with FESEM and FTIR. The DSSC performance was then measured using solar simulator. The current-voltage (I-V) characteristics show that the rGO-SWCNT counter electrode result the excellent performance with efficiency of ~1.86 %, 95.2 % better than graphite. This higher performance was attributed by the complete oxygen-functional group removal during reduction process which offers large active surface area for electro-photocatalytic activity, higher conductivity, better structure and properties compared to the individual forms.
  • Publication
    Remazol orange dye sensitized solar cell using graphene oxide and reduced graphene oxide working electrode
    (Universiti Malaysia Perlis (UniMAP), 2018-12) ;
    Siti S. Mat isa
    ;
    ;
    N. Rosli
    Dye Sensitized Solar Cell (DSSC) is said as a potential solar device which offers easy, cheaper and greener materials and preparation process. However, the efficiency of this device is still an ultimate problem and challenge. In this paper, an organic Remazol orange dye was used as the DSSC dye sensitizer which prepared with different working electrodes. The different working electrodes consist of Titanium Dioxide (TiO2) with Graphene Oxide (GO) and TiO2 with reduced Graphene Oxide (rGO). In order to analyze the adsorption characteristics of GO and rGO, the solution was tested using Ultraviolet-Visible-Near Infrared Spectrophotometry and the surface morphology of all mixed pastes was observed under Atomic Force Microscopy and Scanning Electron Microscope. Then, the device performance was tested under illumination of solar cell simulator. From overall results, the efficiency for all tested devices was quite low from expectation. For this work, the performance of TiO2-rGO DSSC at 0.138% is 84.7% higher compared to the TiO2-GO DSSC which was 0.021%. This result was obtained when the working electrode and dye less exposed to the light during dye preparation process at 24 hours soaking time.