Sheathless Electrospray from Polymer Microchips

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• 作者：Malin Svedberg ; Andreas Pettersson ; Stefan Nilsson ; Jonas Bergquist ; Leif Nyholm ; Fredrik Nikolajeff ; and Karin Markides
• 刊名：Analytical Chemistry
• 出版年：2003
• 出版时间：August 1, 2003
• 年：2003
• 卷：75
• 期：15
• 页码：3934 - 3940
• 全文大小：261K
• 年卷期：v.75,no.15(August 1, 2003)
• ISSN：1520-6882

文摘

In this study, sheathless electrospray from polymermicrochips with conducting layer on the emitter tip isdescribed for the first time. The electrospray emitter tipswere fabricated directly from the end of the microchipsthat were made of polycarbonate or poly(methyl methacrylate) with injection molding. A variety of tip shapesand conducting coatings were evaluated using an electrospray time-of-flight mass spectrometer run in the sheathless mode. Stable electrospray was obtained both fromhand-polished and machine-milled three-dimensional tipscoated with either polymer-embedded gold particles orgraphite particles as the conducting layer. Sputtered gold,on the other hand, suffered from poor stability mainly dueto bad adhesion to the polymer tip. The durability of thedifferent coatings was confirmed with electrochemicalexperiments under simulated electrospray conditions. Therelative standard deviations of the response received fromthe ion current of the MS analysis were in the range of3.5-12%. The detection limit for a standard mixturecontaining five neuropeptides was lower than 0.5 fmol.The low detection limit makes the emitter tips highlyattractive for the analysis of low-abundance biologicalspecies.