A New Sensor Technology Of Fluorescent Nanoparticles For Testing Carcinoma Cells Based On Nano Titanium Dioxide

Nowadays, with the vigorous development of the nanotechnology, some new subjects such as nanochemistry, nanobiology, nanomaterial, nanopharmic are fast developed .Nano-material has been widely used in many fields because of their excellent characteristics such as high ultra-small size effect, surface effect, macroscopic quantum tunneling effect and mechanical, electrical, electrochemical, optical, magnetic and catalytic behaviour. The functional nanoparticles, an important embranchment of the nanomaterial, have become a hot study topic at present. Compared with the traditional biosensor, the senstivity and selectivity of the electrode prepared by nanoparticls have been greatly improved. Many studies indicate that the functional nanoparticle is a kind of perfect tool, which can get life information in situ, in vivo and in real time. Therefore, the studies on the preparation and application of functional nanoparticles are significative. Based on the reaction with an organic dye (rhodamine B isothiocyanat, TRITC) and nanoparticles, we finished our work in following details as follows:1. Preparation of fluorescence nanoparticles with classic sandwich structureThe nano titanium dioxide was synthesized by sol-gel method and nano size gold was gotten by reducing the deoxidized aurum chloride. The fluorescence nanoparticles were obtained by nano titanium dioxide and nanogold sandwiched TRITC with classic network. The physical and chemical properties of the novel nanoparticles have been characterized by using TEM,AFM,XPS, luminescence spectrometer, et al. The results showed that the sandwich fluorescent nanoparticles keep characteristics excellent chemical and optical stability.2. Application of functional fluorescence nanoparticles on testing for the earlier tumourThe sandwich fluorescent nanoparitcles conjugated to the anti-HER2 antibody, can bind specifically to the over-expressing HER2 cells—human ovarian carcinoma SKOV-3 cells using the the bifunctional crosslinker glutaraldehyde. The early recognition and detection of SKOV-3 cells can be realized by using this functional nanoparticle.The results demonstrated that the method using this fluorescent nanoparitcle as labels in place of conventional fluorophore molecular has greatly improved with respect to sensitivity, selectivity, and fluorescent stability in cancer cells recognition. The functional fluorescent nanoparticles can provide a new testing technology in biological assay.3. Quantization of nano-gold based on the variety of fluorescence intensityA new method with better stability used for quantification of nano-gold has been established based on the fluorescence quenching of the aqueous solution of TRITC due to the presence of nano-gold. The experiment conditions of detecting nano-gold were optimized. The nano-gold sol was added into the PBS buffer (pH 6.5) containing TRITC 10 mL(10-5 mol/L), and the fluorescent intensity of the nanoparticles solution was measured after reacting 40 minutes in 40℃water bath. Under the optimum conditions, this method has a detection limit of 2.19 ng/L Au.