The Synthesis And Application Of Fluorescent Silicon Quantum Dots

The fluorescentsilicon quantum dots(f-Si QDs) as a kind of zero-dimensional silicon nanocrystal have attracted an increasing interest for their potential applications in environment,biological,biomedical, solar energy, because of their favorable biocompatibility, low toxicity and excellent photoluminescence properties.This paper focus on the methods of fluorescent silicon quantum dots(Si QDs) preparation and the application of functional,we have try different methods to the decoration on the surface of the Si QDs,and discuss its photoelectric properties and application in ion detection biomedical,sensors. The main work have done as follow:Firstly,the preparation of fluorescentsilicon quantum dots. Blue-green fluorescent silicon quantum dots with a diameter of about 2-3 nm were synthesized by a facile one-step synthesis with etching silicon powder through hydrothermal method at 200?,.compared with other methods which have a serious of advantages such as:simple,convenient,economic,lab acessible. The Si QDs without any surface modification could preserve good water dispersibility, strong photoluminescence and high p H-stability, which can be used as a sensor to detect Cu2+,the lowest Cu2+ concentration that could be detected was 0.5?M, which meets the limit of detection requirement of drinking water.Light response molecules-carboxyl screw pyran to surface modification of silicon quantum dot,with light response performance of the optical fluorescence molecular switches.Spiropyran-modified by chemical bonds on the surface of Si QDs, the reversible modulation of the spiropyran-modified Si QDs is due to the fluorescence resonance energy transfer from the Si QDs to the MC and the transformation of spiropyran moiety structures upon ultraviolet and visible light irradiation. spiropyran modified fluorescent silicon quantum dots molecular switch not only has reversible regulatory light, but also has the corresponding fast, good stability, fatigue resistance, etc.In addition, we also do some job about N-isopropylacrylamide polymerized on the surface of Si QDs, via surface-initiated reversible addition-fragmentation chain transfer(RAFT)polymerization, The fluorescent silicon quantum dots grafted with PNIPAM, a series of different molecular weight inorganic-organic composite materials were preparation with different reaction time.(f-Si QDs-PNIPAM) were characterized using fluorescence spectroscopy, infrared spectroscopy,gel permeation chromatography, etc. Composite nanoparticles are also discussed in terms of temperature detection applications.