Poly(dimethylsiloxane) Contamination in Microcontact Printing and Its Influence on Patterning Oligonucleotides

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• 作者：Christophe Thibault ; Childé ; rick Sé ; verac ; Anne-Franç ; oise Mingotaud ; Christophe Vieu ; Monique Mauzac
• 刊名：Langmuir
• 出版年：2007
• 出版时间：October 9, 2007
• 年：2007
• 卷：23
• 期：21
• 页码：10706 - 10714
• 全文大小：185K
• 年卷期：v.23,no.21(October 9, 2007)
• ISSN：1520-5827

文摘

It is well-established that, during microcontact printing (CP) using poly(dimethylsiloxane) (PDMS)-based stamps,some unexpected siloxane fragments can be transferred from the stamp to the surface of the sample. This so-calledcontamination effect coexists with the delivery of the molecules constituting the ink and by this way influences theprinting process. The real impact of this contamination for the CP technique is still partially unknown. In this work,we investigate the kinetics of this contamination process through the surface characterization of both the sample andthe stamp after imprinting. The way both the curing conditions of the PDMS material and the contact time influencethe degree of contamination of the surface is investigated on silicon and glass substrates. We propose a cleaning processof the stamp during several hours which eliminates any trace of contamination during printing. We show thathydrophobicity recovery of PDMS surfaces after hydrophilic treatment using oxygen plasma is considerably sloweddown when the PDMS material is cleaned using our procedure. Finally, by comparing cleaned and uncleaned PDMSstamps, we show the influence of contamination on the quality of CP using fluorescent DNA molecules as an ink.Surprisingly, we observe that the amount of DNA molecules transferred during CP is higher for the uncleaned stamp,highlighting the positive impact of the presence of low molecular weight siloxane fragments on the CP process. Thisresult is attributed to the better adsorption of oligonucleotides on the stamp surface in presence of these contaminatingmolecules.