Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore.
Langmuir. 2012 Aug 7;28(31):11302-9. doi: 10.1021/la302511e. Epub 2012 Jul 24.
We present the study of silver nanocube (Ag NC)-enhanced fluorescence of a cationic conjugated polyelectrolyte (CPE) for far-red/near-infrared fluorescence cell imaging. Layer-by-layer self-assembly of polyelectrolytes on 78 nm Ag NCs is used to control CPE-metal distance and its effect on CPE fluorescence. The highest fluorescence enhancement factor (FEF) is obtained for Ag NCs with two bilayers, corresponding to a CPE-metal spacer thickness of ~6 nm. At the optimal excitation wavelength, the FEF is 13.8 with respect to the control silica nanoparticles (NPs). The fluorescent NPs are further used for cellular imaging studies. The CPE-loaded Ag NCs with two bilayers exhibit excellent image contrast, superior to the control of CPE-silica NP at a similar uptake efficiency. The viability test indicates low cytotoxicity of the CPE-loaded Ag NCs, rendering them as promising cell imaging agents.
我们研究了银纳米立方体（Ag NC）增强阳离子共轭聚合物电解质（CPE）的远红光/近红外荧光细胞成像。通过层层自组装在 78nm Ag NC 上的聚电解质来控制 CPE-金属距离及其对 CPE 荧光的影响。对于具有两层的 Ag NC，获得了最高的荧光增强因子（FEF），对应于约 6nm 的 CPE-金属间隔厚度。在最佳激发波长下，FEF 相对于对照的二氧化硅纳米颗粒（NPs）为 13.8。进一步将负载 CPE 的 Ag NC 用于细胞成像研究。具有两层的负载 CPE 的 Ag NC 表现出优异的图像对比，优于具有相似摄取效率的对照 CPE-二氧化硅 NP。细胞活力测试表明，负载 CPE 的 Ag NC 的细胞毒性低，有望成为细胞成像试剂。
