Tan Lianjiang, Wan Ajun, Zhu Xiaomin, Li Huili
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Analyst. 2014 Jul 7;139(13):3398-406. doi: 10.1039/c4an00275j.
Bifunctional Ag2S QDs@CS-RBS nanospheres with ultralow toxicity for biomedical use were fabricated. These are capable of releasing NO under irradiation of visible light and emitting in near-infrared (NIR) region fluorescence excited by NIR laser under physiological environment. Glutathiose (GSH)-capped Ag2S QDs were synthesized and encapsulated by chitosan (CS) to form NIR fluorescent Ag2S QDs@CS nanospheres. A type of iron/sulfur/-nitrosyl cluster, Roussin's black salt anion Fe4S3(NO)7(-) (RBS) was conjugated with the Ag2S QDs@CS to obtain Ag2S QDs@CS-RBS nanospheres. A variety of characterization methods were employed to analyze the nanospheres. In vitro cell imaging and in vivo mice imaging experiments demonstrated that the Ag2S QDs@CS-RBS nanospheres could emit readily observable NIR fluorescence and deliver NO in living cells and small animals. The NIR imaging of the Ag2S QDs@CS nanospheres would not interfere with the light-triggered NO release from them, as the excitation lasers needed for these two functions are in different wavelength regions. This work provides new perspectives for the application of multifunctional nano-structured materials in diagnostics and bioimaging.
制备了具有超低毒性、可用于生物医学的双功能硫化银量子点@壳聚糖- Roussin黑盐纳米球。这些纳米球能够在可见光照射下释放一氧化氮，并在生理环境下由近红外（NIR）激光激发后发射近红外区域的荧光。合成了谷胱甘肽（GSH）包覆的硫化银量子点，并将其用壳聚糖（CS）包封，形成近红外荧光硫化银量子点@壳聚糖纳米球。将一种铁/硫/-亚硝酰基簇，即Roussin黑盐阴离子Fe4S3(NO)7(-)（RBS）与硫化银量子点@壳聚糖偶联，得到硫化银量子点@壳聚糖-RBS纳米球。采用多种表征方法对纳米球进行分析。体外细胞成像和体内小鼠成像实验表明，硫化银量子点@壳聚糖-RBS纳米球能够在活细胞和小动物体内发出易于观察的近红外荧光并递送一氧化氮。硫化银量子点@壳聚糖纳米球的近红外成像不会干扰其光触发的一氧化氮释放，因为这两种功能所需的激发激光处于不同的波长区域。这项工作为多功能纳米结构材料在诊断和生物成像中的应用提供了新的视角。
