Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile; Advanced Center for Chronic Diseases (ACCDiS), Santos Dumont 964, Independencia, Santiago, Chile.
Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile; Advanced Center for Chronic Diseases (ACCDiS), Santos Dumont 964, Independencia, Santiago, Chile; Departamento de Ciencias Quimicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Republica 275, Santiago, Chile.
Colloids Surf B Biointerfaces. 2018 Jun 1;166:323-329. doi: 10.1016/j.colsurfb.2018.03.021. Epub 2018 Mar 19.
We studied the photothermal release of carboxyfluorescein (CF) linked to the gold surface of gold nanorods (GNRs) by two Diels-Alder adducts of different lengths (n = 4 and n = 9). The functionalized GNRs were irradiated with infrared light to produce photothermal release of CF by a retro-Diels-Alder reaction. The adducts were chemisorbed on the GNRs and the functionalized nanoparticles were characterized by UV-vis, DLS, zeta potential and Raman and surface-enhanced Raman spectroscopy (SERS). On the basis of the degree of nanoparticle functionalization and the SERS results, we inferred the orientation of CF on the surface of the gold nanoparticle. Moreover, we determined the photothermal release profiles of CF from the gold surface by laser irradiation. The release was faster for the longer linker (n = 9). SERS revealed that, for the shorter linker (n = 4), molecules are oriented perpendicularly with respect to the gold surface, thereby maintaining the CF far from the surface. In contrast, the longer linker was observed to be tilted, thus maintaining CF close to the gold surface and therefore potentially favoring the photothermal transfer of energy. These results are relevant for the future development of the spatial and temporal controlled release of drugs by means of gold nanoparticles.
我们通过两种不同长度(n=4 和 n=9)的二烯-炔加合物研究了连接到金纳米棒(GNRs)金表面的羧基荧光素(CF)的光热释放。功能化的 GNRs 被红外光照射,通过反 Diels-Alder 反应产生 CF 的光热释放。加合物化学吸附在 GNRs 上,并用紫外可见分光光度法、动态光散射、Zeta 电位和拉曼光谱以及表面增强拉曼光谱(SERS)对功能化的纳米粒子进行了表征。基于纳米粒子的功能化程度和 SERS 结果,我们推断了 CF 在金纳米粒子表面的取向。此外,我们通过激光照射确定了 CF 从金表面的光热释放曲线。对于较长的连接体(n=9),释放速度更快。SERS 表明,对于较短的连接体(n=4),分子垂直于金表面取向,从而使 CF 远离表面。相比之下,观察到较长的连接体倾斜,从而使 CF 靠近金表面,因此可能有利于能量的光热传递。这些结果对于未来通过金纳米粒子实现药物的时空可控释放具有重要意义。