Polymeric integrated selective enrichment target (ISET) for solid-phase-based sample preparation in MALDI-TOF MS

A polymer microfabricated proteomic sample preparation and MALDI MS sample presentation device, the integrated selective enrichment target (ISET), comprising an array of perforated nanovials is reported. Each perforated nanovial can be filled with selective extraction media (microbeads) for purification and concentration of protein/peptides prior to matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). The main areas covered are the influence of the molding-process-induced surface roughness and how to address the lack of inherent conductivity in the polyetheretherketone (PEEK) material for optimal MALDI MS readout. Application of the disposable polymeric ISET devices for solid-phase extraction and phosphopeptide capture is also demonstrated.