DNA immobilization on polymer-modified Si surface by controlling pH

• Published in: Applied surface science Vol. 255; no. 13; pp. 6571 - 6576
• Main Authors: Demirel, Gökçen Birlik, Çaykara, Tuncer
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.2009; Elsevier
• Subjects: Biological and medical sciences; Biological techniques and instrumentation; biomedical engineering; Biosensor; Biosensors; Biotechnology; Condensed matter: structure, mechanical and thermal properties; DNA immobilization; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects; Instrumentation. Materials. Reagents. Research laboratory organization; Langmuir-blodgett films; Methods. Procedures. Technologies; pH dependence; Physics; Polymer-modified surface; Self-assembly; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Various methods and equipments; DNA immobilization; pH dependence; Self-assembly; Polymer-modified surface; Biosensor; Self assembly; Atomic force microscopy; Electrostatic interaction; Immobilization; Contact angle; Ellipsometry; DNA; pH; Acrylamide polymer; Fourier transform spectra; Silicon; Infrared spectrum; Molecular mass; Reflectance
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2009.02.042

A novel approach based on polymer-modified Si surface as DNA sensor platforms is presented. The polymer-modified Si surface was prepared by using 3-(methacryloxypropyl)trimethoxysilane [γ-MPS] and poly(acrylamide) [PAAm]. Firstly, a layer of γ-MPS was formed on the hydroxylated silicon surface as a monolayer and then modified with different molecular weight of PAAm to form polymer-modified surface. The polymer-modified Si surface was used for dsDNA immobilization. All steps about formation of layer structure were characterized by ellipsometry, atomic force microscopy (AFM), attenuated total reflectance Fourier transformed infrared (ATR-FTIR), and contact angle (CA) measurements. We found that in this case the amount of dsDNA immobilized onto the surface was dictated by the electrostatic interaction between the substrate surface and the DNA. Our results thus demonstrated that DNA molecules could be immobilized differently onto the polymer-modified support surface via electrostatic interactions.