| 초록 |
Unlike general QDs, the (ZnxAgyInz)S2 nanocrystals could be controlled in a wide range of visible light by change the compositional elements. We have developed a facile and rapid synthesis of highly fluorescent nanocrystal (NC) library, based on ultrasonic and combinatorial chemistry. Among total 66 NCs, many NCs are highly fluorescent upon UV irradiation, and are categorized into blue, green, yellow, orange, and red by their distinct emission wavelength ranges. Although ZAIS shows better fluorescence intensity than QD without photoblinking, it is necessary to enhance its brightness and quantum efficiency for the expansion of its uses, from a cell imaging probe to LED and cosmetic dyes. Here, we developed a rapid and facile synthesis method of ZnS shell surrounding core through ultrasonic chemistry. After adding zinc and sulfur sources to as-prepared core, ZnS shell was successfully formed around core, following the sonication for 10 minutes with an appropriate power. ZnS shells raise their fluorescence intensity up to five or ten times because the sonochemical shell synthesis prevents a lattice mismatch between core and shell, and interface strain due to increasing thickness of shells. Moreover, the quantum efficiency of core-shell nanoparticle increases dramatically from 0.13 to 0.81 in chloroform. For the further application, we prepared MPA (merceptopropionic acid) coated ZAIS-ZnS core-shell nanoparticle to make it dispersed in physiological solution. The population of breast cancer cell didn’t change due to the less-toxic nature of ZAIS-ZnS nanoparticles. |
