Microfabricated electrospray ionization platform with 60 tips for high throughput mass spectrometric analyses

This paper presents a novel multi-tip electrospray ionization (ESI) platform design, which has 60 individual ESI tips. The unique feature of the design is that the tips are located at the periphery of a circular platform. The platform is fixed in front of a mass spectrometer (MS), on a computer controlled rotating table. After each MS measurement a new tip is aligned towards the MS by rotating the table electrically. Our platform design enables high throughput analyses. Sixty MS measurements were done in less than 12 minutes. The fabrication process of silicon-made platform is described in detail. We also demonstrate that a similar microchip could be made of polycarbonate using a high-throughput, low-cost injection compression molding process.