Chen Siqi, Demillo Violeta, Lu Minggen, Zhu Xiaoshan
Department of Electrical and Biomedical Engineering, University of Nevada Reno, NV, USA; Biomedical Engineering Program, University of Nevada Reno, NV, USA.
School of Community Health Sciences, University of Nevada Reno, NV, USA.
RSC Adv. 2016;6(56):51161-51170. doi: 10.1039/C6RA09494E. Epub 2016 May 19.
In this work, high-quality Cu doped AIS and AIS/ZnS NCs have been first synthesized via a surface doping approach. By varying Cu concentrations in doping, Cu doped AIS NCs exhibit a photoluminescence red-shift from around 600 nm to 660 nm with a decrease of quantum yield from around 30% to 20%. After ZnS coating or zinc etching on the Cu doped AIS NCs, Cu doped AIS/ZnS NCs present photoluminescence peaks from around 570 nm to 610 nm and high quantum yields in the range of 50 ~ 60%. Moreover, it is found that Cu doping can prolong the photoluminescence lifetime of NCs, and the average photoluminescence lifetime of Cu doped AIS and AIS/ZnS NCs is in the range of 300 ~ 500 ns. The resultant Cu doped AIS/ZnS NCs were further encapsulated with amphiphilic polymers and used as biocompatible photoluminescent probes in cellular imaging. The cellular imaging study shows that peptide-conjugated probes can specifically target U-87 brain tumor cells and thus they can be applied to the detection of endogenous targets expressed on brain tumor cells.
在本工作中，首次通过表面掺杂方法合成了高质量的铜掺杂铝铟硫（Cu doped AIS）和铝铟硫/硫化锌（AIS/ZnS）纳米晶。通过改变掺杂中的铜浓度，铜掺杂铝铟硫纳米晶的光致发光发生红移，从约600 nm至660 nm，量子产率从约30%降至20%。在对铜掺杂铝铟硫纳米晶进行硫化锌包覆或锌蚀刻后，铜掺杂铝铟硫/硫化锌纳米晶的光致发光峰出现在约570 nm至610 nm，量子产率高达50%至60%。此外，发现铜掺杂可延长纳米晶的光致发光寿命，铜掺杂铝铟硫和铝铟硫/硫化锌纳米晶的平均光致发光寿命在300至500 ns范围内。所得的铜掺杂铝铟硫/硫化锌纳米晶进一步用两亲性聚合物包裹，并用作细胞成像中的生物相容性光致发光探针。细胞成像研究表明，肽缀合探针可以特异性靶向U-87脑肿瘤细胞，因此可应用于检测脑肿瘤细胞上表达的内源性靶点。
