Poletti Annamaria, Fracasso Giulio, Conti Giamaica, Pilot Roberto, Amendola Vincenzo
Department of Chemical Sciences, Università di Padova, Padova, Italy.
Nanoscale. 2015 Aug 28;7(32):13702-14. doi: 10.1039/c5nr03442f. Epub 2015 Jul 29.
Gold nanoparticles with efficient plasmon absorption in the visible and near infrared (NIR) regions, biocompatibility and easy surface functionalization are of interest for photothermal applications. Herein we describe the synthesis and photothermal properties of gold "nanocorals" (AuNC) obtained by laser irradiation of Au nanospheres (AuNS) dispersed in liquid solution. AuNC are formed in two stages: by photofragmentation of AuNS, followed by spontaneous unidirectional assembly of gold nanocrystals. The whole procedure is performed without chemicals or templating compounds, hence the AuNC can be coated with thiolated molecules in one step. We show that AuNC coated with thiolated polymers are easily dispersed in an aqueous environment or in organic solvents and can be included in polymeric matrixes to yield a plasmonic nanocomposite. AuNC dispersions exhibit flat broadband plasmon absorption ranging from the visible to the NIR and unitary light-to-heat conversion. Besides, in vitro biocompatibility experiments assessed the absence of cytotoxic effects even at a dose as high as 100 μg mL(-1). These safe-by-designed AuNC are promising for use in various applications such as photothermal cancer therapy, light-triggered drug release, antimicrobial substrates, optical tomography, obscurant materials and optical coatings.
在可见光和近红外（NIR）区域具有高效等离子体吸收、生物相容性且易于进行表面功能化的金纳米颗粒，在光热应用方面备受关注。在此，我们描述了通过激光辐照分散在液体溶液中的金纳米球（AuNS）所获得的金“纳米珊瑚”（AuNC）的合成及其光热性质。AuNC的形成分为两个阶段：首先是AuNS的光碎片化，随后是金纳米晶体的自发单向组装。整个过程无需化学试剂或模板化合物，因此AuNC可以一步法用硫醇化分子进行包覆。我们表明，包覆有硫醇化聚合物的AuNC易于分散在水性环境或有机溶剂中，并且可以包含在聚合物基质中以形成等离子体纳米复合材料。AuNC分散体在从可见光到近红外范围内表现出平坦的宽带等离子体吸收以及单一的光热转换。此外，体外生物相容性实验评估表明，即使在高达100 μg mL(-1)的剂量下也不存在细胞毒性作用。这些经过设计确保安全的AuNC有望用于多种应用，如光热癌症治疗、光触发药物释放、抗菌基质、光学断层扫描、遮蔽材料和光学涂层。
