Improved Detection of Large Biomolecules in TOF-MS

One of the most desired improvements in the study of high mass biopolymers in time-of-flightmass spectrometry is increased detector sensitivity and efficiency. The innovations we propose willsubstantially improve microchannel plates (MCPs) as detectors of high mass biomolecular ions. This willbe accomplished through implementation of three separate developments: (1) reducing the MCP surfacework function, to increase ion-electron and ion-ion conversion yields leading to improved signal-to-noiseratios (2) enhancing the grazing incidence geometry for incident primary ions through use of a novelsquare channel geometry, also resulting in increased ion-electron and ion-ion yields: and (3) substantiallyimproving MCP detector dynamic range, which has recently been a limiting factor in analyzing heavierbiomolecules in matrix-assisted laser desorption ionization (MALDI). Any one of these improvementswould be considered a worthy incremental enhancement in MCP performance. We will implement allthree simultaneously in the same MCP detector; the result would be a radical departure in theperformance of high mass ion detectors. If this is done, MCP detectors will quickly assume the leadingrole in high mass ion detection in the 50,000 to 1 MegaDalton mass range--just as they are now wellestablished as the leading detectors for low mass ions.