The article of the UMALASERLAB “Spectral Identification in the attogram regime through laser-induced emission of single optically-trapped nanoparticles in air” (Angewandte Chemie International Edition, 2017, 56, 14178) by Pablo Purohit, Fran Fortes and Javier Laserna has been pointed as a 2017 landmark paper in the magazine The Analytical Scientist (January 2018, page 30). According to Vassilia Zorba, from the Lawrence Berkeley National Laboratory, “single nanoparticle analysis was previously unattainable with laser induced breakdown spectroscopy (LIBS), but the authors of my 2017 landmark paper were able to achieve attogram-scale absolute limits of detection by using optical trapping and levitation to isolate single nanoparticles. It represents an entirely new paradigm for high-sensitivity elemental analysis (in an all-optical fashion), opening up new possibilities in single particle analysis”. Single copper nanoparticles with a diameter of only 25 nm, or an equivalent mass of 57 ag, were stably trapped for long periods in air, this being the first time that such a specimens are manipulated and analyzed for elemental composition. “I hope to see future demonstrations of this technology in different nanoparticle systems to assess absolute limits of detection, the use of different laser wavelengths (for example, UV) for LIBS excitation, and the effects of laser pulse duration on analytical figures of merit”, continues Dr. Zorba.

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An article of UMALASERLAB, selected as a landmark paper in The Analytical Scientist