Sirelkhatim, Amna Hassan
(2016)
Surface-Modified Zinc Oxide Nanoparticles And Their Bioactivity Towards Hela Cell Lines, Escherichia Coli And Shigella Flexneri.
PhD thesis, Universiti Sains Malaysia.
Abstract
Objektif utama tesis ini adalah untuk mengkaji struktur and sifat-sifat fiziko-kimia zarah nano zink oksida (ZnO-NPs) dengan hubung kaitnya terhadap aktiviti anti -kanser titisanpada sel kanser serviks manusia (HeLa). Aktiviti antibakteria ZnO-NPs terhadap E.coli and Shigella Flexneri telah diuji untuk mendapatkan kajian penuh mengenai bioaktiviti ZnO-NPs. Tiga sampel ZnO telah digunakan untuk pencirian lengkap bagi sifat-sifat struktur, morfologi (FESEM , TEM, ESI, EDS, XRD), optik (penyerapan UV-Vis dan FTIR), dan keelektrikana (ukuran IV, potensi zeta). Pengubahsuaian pada permukaan telah dilakukan melalui dua pendekatan iaitu penyaduran dengan Pluronic F127 ko-polimer yang telah menstabilkan sampel ZnO-I dan pencahayaan UVA telah menghasilkan sampel ZnO–UVA. TEM dan FESEM menunjukkan rod nano dan mikro sebagai struktur utama dalam ZnO-UVA dan ZnO -I selain daripada plat nano dan mikro dalam struktur dimensi yang berbeza. Manakala ZnO-II terdiri daripada plat nano dan mikro termasuk beberapa nanorods, tetrapod dan struktur lain. Analisis XRD menunjukkan sifat kristal kesemua sampel dan penghabluran. ESI menunjukkan pengagihan Zn dan O atom pada struktur ZnO dengan pemetaan yang menunjukkan nisbah O:Zn. Nisbah Zn yang tinggi menyebabkan kadar pennyaherapan oksigen yang lebih tinggi pada permukaan ZnO-UVA dan ZnO-I yang meningkat kekonduksian-foto (7.51nS dan 5.19nS masing-masing, manakala ZnO-II menunjukkan 1.49nS).
The main objective of this thesis is to investigate the structural, morphological, optical and physiochemical properties of zinc oxide nanoaprticles (ZnO-NPs) with their correlation on anti-cancer activity towards human cervical cancer cell lines (HeLa). The antibacterial activity of ZnO-NPs towards E.coli and Shigella Flexneri was studied as well to get considerable indication of the bioactivity of ZnO-NPs. Three ZnO-NPs samples were used, initially a systematical comprehensive characterization for their structural, morphological (FESEM, TEM, ESI, EDS, XRD), optical (UV-Vis absorption and FTIR), and electrical (I-V measurements, zeta potential) properties have been carried out. Surface modification was performed via coating with Pluronic F-127 copolymer obtained stabilized sample, namely ZnO-I. And UVA illumination, the sample recalled, ZnO-UVA, while the third sample, was bare denoted ZnO-II. TEM and FESEM showed major nano/micro- rods structures in ZnO-UVA and ZnO-I and nano/micro plated structures of different dimensions. ZnO-II showed mainly nano/micro plates and some nanorods, few tetrapod and other structures. TEM showed particle sizes around 80 nm, and XRD analysis revealed the crystallinity of the samples whereas ESI displayed the elemental maps of Zn and O atoms of ZnO structures showing the ratios of O: Zn. Higher Zn ratio resulted in higher desorption of oxygen on ZnO-UVA and ZnO-I surfaces, revealed by the increased photoconductivities of 7.51 nS and 5.19 nS, respectively, while ZnO-II showed 1.49 nS.
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