Study On The Response Of DNA Functionalized Gold Nanoparticles To Ionizing Radiation

Nowadays,in addition to the irradiation of cosmic rays,humans have many radiation caused by artificial or nuclear accidents,and radiation will lead to a series of biological effects.DNA is the carrier of genetic information and the most critical target molecule for radiation-induced biological effects.Heavy ions,ultraviolet light,and X-ray irradiation all cause DNA damage,and the level of aggregate damage that occurs immediately after exposure to radiation can be used as radiation-sensitive detection.Spherical gold nanoparticles have the advantages of size and shape related optoelectronic properties,large surface to volume ratio,excellent biocompatibility and low toxicity.In particular,its ability to surface plasmon resonance(SPR)and quench fluorescence allows gold nanoparticles to find more applications in biosensing and measurement.This thesis aims to combine the radiation-sensitive gene molecules with the nano-effects of nanoparticles,and develop radiation detectors based on nanomaterials and new detection principles for the measurement of Gamma rays.The main research contents are as follows:1.DNA fragments were assembled with gold nanoparticles to prepare radiation-sensitive nanoassemblies.The hypoxanthine guanine phosphoribosyltransferase(HPRT)gene is sensitive to gamma rays.We selected 15 base fragments in different regions of the gene,based on the base sequence of these fragments.Molecular probes with sulfhydryl groups were designed,and these commercially available probes were covalently coupled or base-complemented to the surface of gold nanoparticles by Au-S bonds to form composite nanoassemblies.2.The response of DNA-Au composite nanomaterials to ?-rays.The effect of the radiationsensitive properties of DNA fragments and the surface plasmon resonance of gold nanoparticles on the optical properties of the assembly.The response characteristics of ionizing radiation were observed by UV-Vis spectrometer.The quantitative relationship between the light absorption and the radiation dose of the assembly was obtained by quantitative detection of the color change of the solution.3.Radiation-sensitive enhancement effects of Au nanoparticle surface plasmon resonance.The Raman scattering spectrum of the DNA-Au nanoassembly on a gold substrate was measured by surface enhanced Raman scattering(SERS)spectroscopy.Due to the enhanced effect of the gold matrix on the local electric field,the structural changes of the gold nanoassembly due to ionizing radiation are sensitively presented on the Raman scattering spectrum,increasing the sensitivity to ionizing radiation detection.