Al-Kattan Ahmed, Tselikov Gleb, Metwally Khaled, Popov Anton A, Mensah Serge, Kabashin Andrei V
Aix-Marseille University, CNRS, LP3, Campus de Luminy, 13013 Marseille, France.
Moscow Institute of Physics and Technology, Center for Photonics and 2D Materials, 141700 Dolgoprudny, Russia.
Nanomaterials (Basel). 2021 Feb 26;11(3):592. doi: 10.3390/nano11030592.
Owing to strong plasmonic absorption and excellent biocompatibility, gold nanostructures are among best candidates for photoacoustic bioimaging and photothermal therapy, but such applications require ultrapure Au-based nanoformulations of complex geometry (core-shells, nanorods) in order to shift the absorption band toward the region of relative tissue transparency (650-1000 nm). Here, we present a methodology for the fabrication of Si@Au core-satellite nanostructures, comprising of a Si core covered with small Au nanoparticles (NP), based on laser ablative synthesis of Si and Au NPs in water/ethanol solutions, followed by a chemical modification of the Si NPs by 3-aminopropyltrimethoxysilane (APTMS) and their subsequent decoration by the Au NPs. We show that the formed core-satellites have a red-shifted plasmonic absorption feature compared to that of pure Au NPs (520 nm), with the position of the peak depending on APTMS amount, water-ethanol solvent percentage and Si-Au volume ratio. As an example, even relatively small 40-nm core-satellites (34 nm Si core + 4 nm Au shell) provided a much red shifted peak centered around 610 nm and having a large tail over 700 nm. The generation of the plasmonic peak is confirmed by modeling of Si@Au core-shells of relevant parameters via Mie theory. Being relatively small and exempt of any toxic impurity due to ultraclean laser synthesis, the Si@Au core-satellites promise a major advancement of imaging and phototherapy modalities based on plasmonic properties of nanomaterials.
由于具有强烈的等离子体吸收特性和出色的生物相容性，金纳米结构是光声生物成像和光热疗法的最佳候选材料之一，但此类应用需要具有复杂几何形状（核壳结构、纳米棒）的超纯金基纳米制剂，以便将吸收带移向相对组织透明的区域（650 - 1000 nm）。在此，我们提出一种制备Si@Au核 - 卫星纳米结构的方法，该结构由覆盖有小金纳米颗粒（NP）的硅核组成，基于在水/乙醇溶液中通过激光烧蚀合成硅和金纳米颗粒，随后用3 - 氨丙基三甲氧基硅烷（APTMS）对硅纳米颗粒进行化学修饰，并随后用金纳米颗粒进行装饰。我们表明，与纯金纳米颗粒（520 nm）相比，形成的核 - 卫星结构具有红移的等离子体吸收特征，其峰值位置取决于APTMS的量、水 - 乙醇溶剂百分比和硅 - 金体积比。例如，即使是相对较小的40纳米核 - 卫星结构（34纳米硅核 + 4纳米金壳）也提供了一个红移得多的峰值，中心约在610纳米，并且在700纳米以上有一个大的拖尾峰。通过米氏理论对相关参数的Si@Au核壳结构进行建模，证实了等离子体峰的产生。由于超清洁激光合成，Si@Au核 - 卫星结构相对较小且不含任何有毒杂质，有望基于纳米材料的等离子体特性在成像和光疗模式方面取得重大进展。
