Interactions between water-soluble CdSe quantum dots and gold nanoparticles studied by UV-visible absorption spectroscopy

The interaction of water-soluble CdSe quantum dots (QDs) with gold (Au) nanoparticles was investigated by ultraviolet visible absorption spectroscopy. The results showed that the aggregation of Au nanoparticles was induced by CdSe QDs. The influences of factors such as the size of An nanoparticles, acidity, buffer concentration and the concentration ratio of the CdSe QDs to Au nanoparticles were each investigated. The comparison of two different particle sizes (16 and 25 nm) of Au nanoparticles that interact with CdSe QDs in the solution showed that the aggregation of small Au nanoparticles (16 nm) is easier than that of big Au nanoparticles (25 nm). At pH 7.0 phosphate buffer solution (0.02 M), the optimal molar ratio of CdSe:Au is about 3 100:1 according to calculations.

利用紫外 - 可见吸收光谱研究了水溶性CdSe量子点（QDs）与金（Au）纳米粒子的相互作用。结果表明，CdSe量子点诱导了Au纳米粒子的聚集。分别研究了Au纳米粒子的尺寸、酸度、缓冲液浓度以及CdSe量子点与Au纳米粒子的浓度比等因素的影响。对溶液中两种不同粒径（16和25 nm）的Au纳米粒子与CdSe量子点相互作用的比较表明，小粒径Au纳米粒子（16 nm）比大粒径Au纳米粒子（25 nm）更容易聚集。在pH 7.0的磷酸盐缓冲溶液（0.02 M）中，经计算，CdSe与Au的最佳摩尔比约为3100∶1。