Research On The Synthesis Of Cu?Ag?InS₂ Quantum Dots And Their Application On Fluorescent Probe

CuInS₂ quantum dots?CIS QDs?and AgInS₂ quantum dots?AIS QDs?are the new-type ternary quantum dots?I-III-VI₂ QDs?.CIS QDs and AIS QDs got rapid development because of its low toxicity and were believed to be one of the main green materials to replace traditional Cd-and Pb-quantum dots.CIS QDs and AIS QDs have non-toxic,big absorption coefficient,wide band gap,large stokes shift,good stability,convenient and adjustable fluorescence emission spectrum.All these properties made CIS QDs and AIS QDs have been widely applied in many aspects of the biological and physical.But most of the synthesis method used in the synthesis process is in organic phase.The quantum dots prepared there have many defects which limit its application in biology.So finding a kind of water phase synthesis method of green environmental protection is particularly important.In the water phase synthetic process of CIS and CIS/ZnS quantum dots with different molar ratios of Cu:In,we prepared water-soluble quantum dots modified by glutathione.The fluorescence emission spectrum of CIS/ZnS quantum dots can red-shifted from 500 nm to 680 nm with changing the molar ratios of Cu:In which ranged from green light to near infrared light.Through characterizing the CIS/ZnS quantum dots with various characterization methods,we found the average particle size of CIS/ZnS QDs was only 1.8 nm and particle size distribution possessed uniform.The CIS/ZnS quantum dots belonged to the sphalerite structure and had stable fluorescence properties.We prepared the CIS/ZnS QDs which the molar ratio of Cu:In is 1:8 as fluorescent probe to function with ascorbic acid and realized the quantitative detection against the solution concentration of ascorbic acid.We also prepared AIS quantum dots with different molar ratios of Ag:In modified with PEI and MPA through the method of aqueous-phase synthesis.The fluorescence emission spectrum of AIS QDs shifted from 530 nm to 670 nm which is ranged from the green light to red light.By characterizing the AIS quantum dots with all kinds of characterization methods,we found the average particle size of AIS QDs was only 2.1 nm and particle size distribution possessed uniform in solution.The CIS/ZnS quantum dots belonged to the phase chalcopyrite structure and had stable fluorescence properties.And we prepared AIS quantum dots which the moalr ratio of Ag:In is 1:9 as the fluorescent probe to interact with dopamine and realized the quantitative detection of dopamine solution concentration.