Well-dispersed CdS quantum dots (QDs) with narrow size-distribution were prepared using generation 4.5 ester-terminated PAMAM dendrimers as inner-templates. The average diameter of CdS QDs was 1.5 nm and the photolumi...Well-dispersed CdS quantum dots (QDs) with narrow size-distribution were prepared using generation 4.5 ester-terminated PAMAM dendrimers as inner-templates. The average diameter of CdS QDs was 1.5 nm and the photoluminescence was purple. The room temperature photoluminescence quantum yield (RT-PQY) was 0.015. The diameter of CdS QDs increased with the increase of n / nPAMAM, also the color of photoluminescence was tunable and could be changed from purple to blue.展开更多
目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚...目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚合物还可以钝化材料,为粒子提供良好的表面状态。其中树状大分子因为具有独特的结构,特别适合做金属纳米粒子的主体。通过树状大分子的封装或包裹,纳米级的金属原子簇或胶体粒子保持稳定。用于树枝状大分子保护的金属簇(化合物)纳米粒子的制备研究主要采用PAMAM多代树状大分子。按照文献的方法,合成3.5 G PAMAM树状大分子做保护剂,从而制备了CdS纳米粒子,得到的粒子大小均匀。本文同时考察了3.5 G PAMAM与CdS不同物质的量比时对制得的纳米粒子的大小、尺寸的影响情况。展开更多
A novel photoelectrochemical biosensor incorporating nanosized CdS semiconductor crystals with enzyme to enhance photochemical reaction has been investigated. CdS nanoparticles were synthesized by using dendrimer PAMA...A novel photoelectrochemical biosensor incorporating nanosized CdS semiconductor crystals with enzyme to enhance photochemical reaction has been investigated. CdS nanoparticles were synthesized by using dendrimer PAMAM as inner templates. The CdS nanoparticles and glucose oxidase （GOD） were immobilized on Pt electrode via layer-by-layer （LbL） technique to fabricate a biological-inorganic hybrid system. Under ultraviolet light, the photo-effect of the CdS nanoparticles showed enhancement of the biosensor to detect glucose. Pt nanoparticles were mixed into the Nation film to immobilize the CdS/enzyme composites and to improve the charge transfer of the hybrid. Experimental results demonstrate the desirable characteristics of this biosensing system, e,g. a sensitivity of 1.83 μA/（mM cm^2）, lower detection limit （1 μM）, and acceptable reproducibility and stability,展开更多
文摘Well-dispersed CdS quantum dots (QDs) with narrow size-distribution were prepared using generation 4.5 ester-terminated PAMAM dendrimers as inner-templates. The average diameter of CdS QDs was 1.5 nm and the photoluminescence was purple. The room temperature photoluminescence quantum yield (RT-PQY) was 0.015. The diameter of CdS QDs increased with the increase of n / nPAMAM, also the color of photoluminescence was tunable and could be changed from purple to blue.
文摘目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚合物还可以钝化材料,为粒子提供良好的表面状态。其中树状大分子因为具有独特的结构,特别适合做金属纳米粒子的主体。通过树状大分子的封装或包裹,纳米级的金属原子簇或胶体粒子保持稳定。用于树枝状大分子保护的金属簇(化合物)纳米粒子的制备研究主要采用PAMAM多代树状大分子。按照文献的方法,合成3.5 G PAMAM树状大分子做保护剂,从而制备了CdS纳米粒子,得到的粒子大小均匀。本文同时考察了3.5 G PAMAM与CdS不同物质的量比时对制得的纳米粒子的大小、尺寸的影响情况。
基金support from the National Natural Science Foundation of China (Grant No.20676038)the Key Project of Science and Technology for Ministry of Education (Grant No. 107045)+1 种基金the Program of Shanghai Subject Chief Scientist (08XD1401500)the Shanghai Leading Academic Discipline Project (Project Number:B502)
文摘A novel photoelectrochemical biosensor incorporating nanosized CdS semiconductor crystals with enzyme to enhance photochemical reaction has been investigated. CdS nanoparticles were synthesized by using dendrimer PAMAM as inner templates. The CdS nanoparticles and glucose oxidase （GOD） were immobilized on Pt electrode via layer-by-layer （LbL） technique to fabricate a biological-inorganic hybrid system. Under ultraviolet light, the photo-effect of the CdS nanoparticles showed enhancement of the biosensor to detect glucose. Pt nanoparticles were mixed into the Nation film to immobilize the CdS/enzyme composites and to improve the charge transfer of the hybrid. Experimental results demonstrate the desirable characteristics of this biosensing system, e,g. a sensitivity of 1.83 μA/（mM cm^2）, lower detection limit （1 μM）, and acceptable reproducibility and stability,
