Gel filtration is a versatile technique employed for biological molecules and nanoparticles, offering their reproducible classification based on size and shape. Colloidal nanoparticles are of significant interest in biomedical applications due to a large number of solution-based bioconjugation procedures. Nevertheless, the inherent polydispersity of the nanoparticles produced by various techniques necessitates the employment of high yield separation and purification techniques. Here we demonstrate the employment of gel filtration on non-stoichiometric plasmonic MoO x nanoparticles, prepared by an oxidation process during liquid-phase exfoliation of few-layer MoS2 nanosheets. This resulted in the separation of two types of MoO x particles, in the form of two different chromatographic fractions. They showed different sizes, morphological and optical properties. The fraction containing smaller particles with diameters of 1-4 nm, exhibited an increased absorbance peak in the near IR region and responded with a significant temperature increase to laser irradiation at the wavelength close to the maximal absorption. The fraction with the larger particles from 3 up to 10 nm, showed weak photoluminescence and a preferred orientation upon the deposition on a planar substrate. However, it had no absorbance in the near IR compared to the former fraction. According to our knowledge, this is the first time that the gel filtration was applied to the separation of molybdenum oxide nanomaterials. This step ensured the isolation of plasmonic MoO x nanoparticles suitable for further bioconjugation and target photothermal treatment.

中文翻译：

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通过凝胶过滤从少层 MoS2 剥离副产物中提取 MoOx 光热活性纳米粒子


凝胶过滤是一种用于生物分子和纳米颗粒的通用技术，可根据尺寸和形状对其进行可重复的分类。由于大量基于溶液的生物共轭过程，胶体纳米粒子在生物医学应用中引起了极大的兴趣。然而，通过各种技术产生的纳米颗粒固有的多分散性需要采用高产率分离和纯化技术。在这里，我们展示了对非化学计量等离激元 MoO x 纳米颗粒的凝胶过滤的应用，该纳米颗粒是通过少层 MoS2 纳米片的液相剥离过程中的氧化过程制备的。这导致两种类型的 MoO x 颗粒以两种不同色谱级分的形式分离。它们表现出不同的尺寸、形态和光学特性。含有直径为 1-4 nm 的较小颗粒的部分在近红外区域表现出增加的吸收峰，并且在接近最大吸收的波长处对激光照射的温度显着升高做出响应。具有 3 至 10 nm 的较大颗粒的部分在平面基底上沉积时显示出弱光致发光和优选取向。然而，与前一组分相比，它在近红外区域没有吸光度。据了解，这是首次将凝胶过滤应用于氧化钼纳米材料的分离。此步骤确保了等离子体 MoO x 纳米颗粒的分离，适合进一步的生物共轭和目标光热处理。