Spatially dynamic laser patterning using advanced optics for imaging matrix assisted laser desorption/ionization (MALDI) mass spectrometry

Beam homogenization and spatially dynamic beam patterning optics have been combined to improve the imaging matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI–TOFMS) experiment. The optical design was developed to improve upon the spatial resolution limit imposed by the laser beam profile (∼25–50 μm) and to decrease the long analysis times associated with mechanical translation of the MALDI sample stage. This arrangement consists of: laser beam conditioning optics, laser beam shaping optics via a digital micromirror device (DMD), and an imaging lens system. Experimental results comparing traditional imaging MALDI–TOFMS and spatially dynamic imaging MALDI–TOFMS are discussed. The optical system has proven useful for patterning the MALDI laser beam into user defined beam shapes, can potentially decrease analysis times associated with mechanical movement of the sample stage, and may be capable of increasing the limits of detection by simultaneously irradiating multiple spots.