Nanoscale laser-induced breakdown spectroscopy imaging reveals chemical distribution with subcellular resolution
Understanding chemical compositions is one of the most important parts in exploring the micro world. As a simple method for elemental detection, laser-induced breakdown spectroscopy (LIBS) is widely used in material, geological and life science fields. However, due to the long-existing limitation in spatial resolution, LIBS is difficult to play an analytical role in the field of low microns or even nanometers. Herein, we firstly report a reliable nanoscale resolution LIBS imaging technique by introducing the sampling laser with a micro-lensed fiber. Through the emission enhancement by double-pulse laser, we obtained the spectral signal from a sampling crater of less than 500 nanometers in diameter, and visualized the chemical distribution of the self-made grid sample, SIM chip and nano-particles in single cells. The relative limits of detection (RLOD) of In and absolute limits of detection (ALOD) of Al can reach 0.6% and 18.3 fg, respectively.