DNA ile fonksiyonellendirilmiş silika kaplı ɣ-Fe2O3 manyetik nanopartiküllerin spektroskopik, morfolojik ve elektrokimyasal empedans ile karakterizasyonu

Silica coated magnetic iron oxide nanoparticles (SiMAG, special name of the product) at maghemite form (ɣ-Fe2O3 NPs) were obtained from Chemicell Company (Belgium). Different DNA oligonucleotides (Cola, 3C-Cola, and 6C-Cola) were bound to the surface of silica coated magnetic iron oxide NPs (SiMAG) by Sentromer DNA Technologies Company. Additionally, magnetic iron oxide nanoparticles on magnetite form (Fe3O4) was also synthesized. Then, magnetite iron oxide nanoparticles were converted to maghemite form (ɣ-Fe2O3) by calcination proces at 300°C. After that, ɣ-Fe2O3 NPs were coated with silica. Therefore, silica coated ɣ-Fe2O3 NPs that have same structural form as SiMAG were obtained. Both synthesized silica coated ɣ-Fe2O3 NPs and SiMAG nanoparticles were characterized spectroscopically with Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR), Raman Spectrophotometer, and UV-Vis spectrophotometer. Analysis results were compared in each other. It was observed that both of magnetic nanoparticles had same structure and formation owing to exhibition same characteristic bands from the analyses. In additional, DNA oligonucleotides (ttr4, and dT20) and magnetic nanoparticles with and without DNA binding (SiMAG, SiMAG-Cola, SiMAG-3C-Cola, SiMAG-6C-Cola, and SiMAG-30T) were investigated spectroscopically (UV-Vis Spectrophotometer), morphologically (AFM and SEM), and electrochemically (Electrochemical Impedance Spectroscopy (EIS)). The effect of parameters such as concentration, presence of bound DNA, length of DNA on impedance, capacitance, UV absorbance and granule size were investigated. As a result of the measurements, it was observed that when the concentration was increased, Cdl (double layer capacitance) and CLF (Low frequency capacitance) values decreased while |Z| (impedance) and UV absorbance values increased. Moreover, when the DNA oligonucleotide was bound to the magnetic nanoparticle and the length of DNA oligonucleotide was elongated from 12 base to 30 base, it was observed that granule diameters were expanded, the |Z| values diminished, Cdl and CLF values increased for each concentration value.