Microfluidic devices for protein analysis using intact and top-down mass spectrometry

Top-down mass spectrometry (TD-MS) provides unique information on compositions, structures, and functions of proteins or protein complexes and has been recognized as a powerful approach to complement conventional tools in protein analysis. Employing microfluidic chips in TD-MS workflows offers unique advantages including flexible integration and automation of multiple sample treatment functions, lowered sample consumption, compatibility with high-sensitive ionization and higher throughput. Here we reviewed the reported microchips developed for TD-MS in aspects of design of ionization, separation and mixing modules, and fabrication approaches; we also attempted to summarize the design considerations that may inspire development of microchips with better performance and wider applications.