Departamento de Química Analítica, Universidad de Málaga, Campus de Teatinos S/N, 29071, Málaga, Spain.
Angew Chem Int Ed Engl. 2017 Nov 6;56(45):14178-14182. doi: 10.1002/anie.201708870. Epub 2017 Oct 4.
Current trends in nanoengineering are bringing along new structures of diverse chemical compositions that need to be meticulously defined in order to ensure their correct operation. Few methods can provide the sensitivity required to carry out measurements on individual nano-objects without tedious sample pre-treatment or data analysis. In the present study, we introduce a pathway for the elemental identification of single nanoparticles (NPs) that avoids suspension in liquid media by means of optical trapping and laser-induced plasma spectroscopy. We demonstrate spectroscopic detection and identification of individual 25(±3.7) to 70(±10.5) nm in diameter Cu NPs stably trapped in air featuring masses down to 73±35 attograms. We found an increase in the absolute number of photons produced as size of the particles decreased; pointing towards a more efficient excitation of ensembles of only ca. 7×10 Cu atoms in the onset plasma.
当前的纳米工程趋势带来了具有不同化学成分的新型结构，这些结构需要进行精心定义，以确保其正确运行。很少有方法可以在不进行繁琐的样品预处理或数据分析的情况下提供对单个纳米物体进行测量所需的灵敏度。在本研究中，我们通过光学捕获和激光诱导等离子体光谱法，引入了一种避免悬浮在液体介质中的单纳米颗粒 (NP) 元素识别途径。我们展示了直径为 25(±3.7) 至 70(±10.5)nm 的单个 Cu NPs 的光谱检测和识别，这些 NPs 在空气中稳定捕获，质量低至 73±35 飞克。我们发现随着颗粒尺寸的减小，产生的光子绝对数量增加；这表明在起始等离子体中，只有约 7×10 个 Cu 原子的集合的激发效率更高。
