Break Free of the Matrix: Sensitive and Rapid Analysis of Small Molecules Using Nanostructured Surfaces and LDI-TOF Mass Spectrometry

Abstract

We describe a novel nanostructured target plate for laser desorption/ionization (LDI) mass spectrometry, NALDI (Bruker Daltonics, Billerica, MA) target plates. The active surface comprises several layers of inorganic materials that are structured at the nanoscale and then further coated with a hydrophobic organic layer that facilitates sample deposition and LDI performance. These targets have been designed to analyze low mass (below 1500 Da), relatively polar, organic molecules and they have been shown to be up to 10 times more sensitive at detecting analytes in this range than conventional Matrix-assisted laser desorption/ionization—Time of Flight (MALDI)-TOF analysis. The targets can be used on standard LDI-TOF mass spectrometers and have been designed to fit the Bruker Flex series of mass spectrometers. This study demonstrates the utility of these targets for analyzing pharmaceutical compounds and demonstrates their superiority over conventional MALDI both in terms of performance and ease of use. Finally, we also demonstrate that these targets can be used in a unique sample preparation and analysis mode by allowing the capture and analysis of analytes from complex biological solutions.