Organophosphonate-Based PNA-Functionalization of Silicon Nanowires for Label-Free DNA Detection

详细信息    查看全文

• 作者：Anna Cattani-Scholz ; Daniel Pedone ; Manish Dubey ; Stefan Neppl ; Bert Nickel ; Peter Feulner ; Jeffrey Schwartz ; Gerhard Abstreiter ; Marc Tornow
• 刊名：ACS Nano
• 出版年：2008
• 出版时间：August 26, 2008
• 年：2008
• 卷：2
• 期：8
• 页码：1653-1660
• 全文大小：338K
• 年卷期：0
• ISSN：1936-086X

文摘

We investigated hydroxyalkylphosphonate monolayers as a novel platform for the biofunctionalization of silicon-based field effect sensor devices. This included a detailed study of the thin film properties of organophosphonate films on Si substrates using several surface analysis techniques, including AFM, ellipsometry, contact angle, X-ray photoelectron spectroscopy (XPS), X-ray reflectivity, and current−voltage characteristics in electrolyte solution. Our results indicate the formation of a dense monolayer on the native silicon oxide that has excellent passivation properties. The monolayer was biofunctionalized with 12 mer peptide nucleic acid (PNA) receptor molecules in a two-step procedure using the heterobifunctional linker, 3-maleimidopropionic-acid-N-hydroxysuccinimidester. Successful surface modification with the probe PNA was verified by XPS and contact angle measurements, and hybridization with DNA was determined by fluorescence measurements. Finally, the PNA functionalization protocol was translated to 2 μm long, 100 nm wide Si nanowire field effect devices, which were successfully used for label-free DNA/PNA hybridization detection.