L-半胱氨酸修饰的ZnS:Co/ZnS量子点的合成及表征  

Synthesis and Characterization of L-Cysteine-modified ZnS:Co/ZnS Quantum Dots

作　　者：孙聪[1] 黄风华[1] 

机构地区：[1]福建师范大学化学与化工学院,福州350007

出　　处：《人工晶体学报》2013年第10期2028-2032,共5页Journal of Synthetic Crystals

基　　金：福建省自然科学基金(2009J01022)

摘　　要：选用L-半胱氨酸作为修饰剂,采用共沉淀法在水溶液中合成了ZnS∶Co/ZnS量子点。通过X-射线粉末衍射(XRD)、透射电镜(TEM)、红外光谱(IR)、紫外可见光谱(UV-Vis)和荧光光谱(PL)对量子点的结构、形貌、组成及光谱性质进行表征。结果表明:ZnS∶Co/ZnS量子点为立方闪锌矿结构,颗粒呈球形,分散性好,颗粒尺寸约为3.3nm;随着ZnS壳层增厚,ZnS∶Co/ZnS量子点的荧光发射峰强度先增大后减小,核壳比为1∶0.15时发光强度达到最大。Co2+的掺杂和ZnS壳层的形成使量子点的荧光量子产率从2.4%增加到9.8%。L-半胱氨酸分子通过其巯基与量子点表面的金属离子配位,从而修饰在量子点的表面,使该量子点具有水溶性、生物相容性和生物可偶联性。ZnS： Co/ZnS quantum dots have been synthesized by chemical co-precipitation method using L- cysteine as stabilizer in aqueous solution. The structure, morphology, component and fluorescence properties of the quantum dots were characterized by XRD, TEM, IR, UV-Vis and PL. The results showed that ZnS： Co/ZnS quantum dots were spherical with diameter around 3. 3 nm, owned good monodispersity and belonged to the cubic blende structure. The PL intensity of ZnS： Co/ZnS quantum dots increased at the beginning and decreased with further growth of the ZnS shell. The PL intensity of ZnS： Co/ZnS achieved the maximum when no/ns = 1 ： 0.15. The fluorescence quantum yield of the as- prepared quantum dots inscreaed from 2.4% to 9.8% after doped with Co2＋ and coated with ZnS shell. The sulfur atoms in L-cysteine molecules were coordinated with metal ions on the surface of quantum dots. The L-cysteine modified on the surface of ZnS： Co/ZnS quantum dots renders the quantum dots water-soluble and biocompatible.

关 键 词：ZNS CO ZnS量子点 L-半胱氨酸 合成 荧光 

分 类 号：O773[理学—晶体学]