The Preparation Of Selenium Nano-light-Scattering Spectroprobes And Their Applications In Biochemical Analysis

The properties of light scattering are another important optical property of nanoparticles in addition to absorption,etc.By using the light scattering properties of nanoparticles,high sensitivity analysis and high resolution imaging of the targets can be realized by dark field microscopy.But the traditional light scattering probes,such as gold and silver nanoparticles,are expensive and are not easy to preserve for long time.Recently,the inorganic non-metallic selenium nanoparticles,such as selenium nanoparticles,selenium nanoparticles doped with non-metal and selenium nanoparticles doped with metal,as a semiconductor nanomaterials have received wide attention.Especially,compared with many metals and metal oxides,selenium nanoparticles show better water-solubility and biocompatibility,more superior antibacterial,anti-cancer and anti-inflammatory effect,lower toxicity.Therefore the selenium nanoparticles are used in many fields such as antibacterial,anticancer,imaging and drug delivery,etc.However,the light scattering properties of the selenium nanoparticles,especially selenium nanoparticles,have not yet been explored.Grasping their light scattering properties is of great significance for us to have a compete understanding of the properties of the materials,to expand their application fields,then achieving a better service for mankindy.Therefore,in this thesis,taking the development of new light scattering probes into consideration,the research is divided into three contents as follows:1.The hydrothermal synthesis of selenium nanoparticles(SeNPs)and the dark-field microscopy(DFM)imaging of nucleolin of nucleolus(NCL).A semiconductor SeNPs can be synthesized through hydrothermal synthesis method with ascorbic acid and selenium dioxide as raw materials.The as-prepared SeNPs show good water solubility and biocompatibility.Under DFM,the SeNPs show strong green scattering light with a characterized scattering peak at 570 nm,and a selenium nanoparticle can be compared to1.34×10~5 fluorescein molecules in terms of light-producing power,meaning that the SeNPs can act as good light scattering probes.The scattering light of SeNPs is derived from the various electron and magnetic resonance.Furthermore,the SeNPs can precisely and specifically target and image NCL overexpressing cancer cells after being modified with aptamers.By this,we design and develop SeNPs as a new light scattering nanoprobe for DFM imaging of NCL.2.Hydrothermal synthesis of selenium sulfide nanoparticles(SeSNPs)and the real-time microscopy imaging of phase transition.A semiconductor SeSNPs doped with sulfur is preparaed by hydrothermal synthesis with selenium dioxide and L-cysteine as raw materials.The synthesized SeSNPs with amorphous structure show red scattering light,and the characteristic scattering peaks are located at 620 nm.The scattering light of SeSNPs is also caused by the various electron and magnetic resonance.The phase of selenium sulphide nanoparticles(SeSNPs)can occur to change from amorphous to polycrystalline via mercury ions permeation at room temperature.The phase transformation induces a color change of SeSNPs in DFM and a scattering spectral blue-shift.Baesd on this,we develop a valuable imaging technique for real-time monitoring of phase transformation in materials chemistry at the single nanoparticle level through DFM.3.Hydrothermal synthesis of dendritic copper selenide(CuSe)and theefficient adsorption and photocatalytic degradation of malachite green(MG).Inspired by the green synthesis method,we develop a one-pot green hydrothermal routeto prepare hierarchical side-branched dendritic CuSe by using natural kiwi juice as the reducing andcoating reagent.Due to their low optical band gap(1.57 eV)andhigh specific surface areas,the dendritic CuSe can achievehighly effective degradation of MG under the synergistic effect of strong adsorption capacity and efficient photocatalytic activity.Undernatural daylight,the degradation ratereaches 97%within 30 min by using the dendritic CuSe,indicatingthat the dendrite CuSe can be used as a desirable candidate forenvironmental remediation.In conclusion,two kinds of Inorganic nonmetallic light scattering probes are preparaed by one-step hydrothermal synthesis method.The semiconductor SeNPs show bright green scattering light,and can realize the dark-field imaging of the NCL over-expressed on cancer cell membrane after modified with the special aptamers,thus the SeNPs can act as a good light scattering nanoprobe for bioimaging and biolabeling.SeSNPs dopping with non-metallic sulfur element show red scattering light,and can be used for real-time imaging the phase transformation at the single nanoparticle level by using DFM.This is the first time that a phase transformation has been monitored at the single nanoparticle level.Based on this,we can try to use the dark-field imaging technology to real-time monitor the changes of the internal structure of individual nanoparticles.Futhermore,the dendritic CuSe dopping with metallic copper element,developed by hydrothermal method,achieves the efficient adsorption and photocatalytic degradation towarding the organic dyes.