Gold Nanoparticles Control Quantum Dot Hyperradiation Research

Quantum dots as emerging in biological detection of a fluorescent marker,it compared with semiconductor material appeared some special photoelectric characteristic,therefore in the biomarkers,detection,light-emitting devices,and other research category has a larger development vision.Due to the enhanced effect of surface photoelectric signal and low toxicity side effects,the gold nanoparticles are widely used in the fields of medicine and biometrics.Under the right conditions,precious metals nano structure surface plasmon resonance effect can effectively enhance the radiation attenuation,quantum dots is through this method to enhance the fluorescent to improve the sensitivity of based on quantum dots biological detection system has become research hotspot issues.This paper which was based on the theoretical model of strengthening the quantum point superradiation effect of the gold nanostructure,and had been studied experimentally.The quantum dots clusters was considered as the research object,using laser spots with nano scale to study fluorescent properties of the single QDs cluster,and its compound membrane on scanning near-field optical microscopy.The main research work and important results of this paper were also explored as: 1.The superradiance of QDs method.In this paper we applied theory of Wannier exciton to quantum dots cluster in Dicke model,and the cubic relationship between the radius of quantum dots clusters and their radiative decay rate was proved theoretically.The fluorescence spectra of quantum dots and the superradiance spectrum of each single quantum dots cluster were characterized by fluorescence spectrophotometer the Scanning Near-field Microscope experimentally.The experimental results basically match with our theoretical model when the size was smaller than 55 nm.On the country,as its size was bigger than 55 nm,enhancement tendency of the superradiant effects was slow down,due to the sizes of QDs cluster was relatively large,the interaction among QDs was so strong that fluorescence quenching effects took place,which weakens their superradiant effects and results in their deviation from the theoretical curve;2.Gold nanoparticles control quantum dot clusters of radiation.Radiation attenuation model was used to describe this process,by controlling the thickness of the polyelectrolyte film to regulate the distance between gold nanoparticles and quantum dots.Experiments show that the thickness of the polyelectrolyte quantum dots in 14 nm largest collection of fluorescence enhancement effect,enhance the effect of 1.4 times.From experimental effective way to increase the quantum dots radiation attenuation,further enhance the fluorescence intensity of the quantum dot collection,so as to meet the needs of the biological detection and high sensitivity.