DNA immobilization silanization

Fig. 6 Common silanizing trialkoxysilanes that promote covalent DNA immobilization a 3-aminopropyltriethoxysilane (APTES) b 3-aminopropyltrimethoxysilane (APTMS) c 3-glycidoxypropyltrimethoxysUane (GOPS) d 3-mercaptopropyltrimethoxysilane (MPTS)...

Examples of the various methods of DNA immobilization are shown in Fig. 5. Amongst these are physical adsorption and covalent immobilization. The covalent immobihzation is best exemplified by the use of organo-silane chemistries and alkanethiol chemistries. 

Fig. 6 Common silanizing agents to promote covalent DNA immobilization a 3-amino-propyltrimethoxysilane (APS) b 3-mercaptopropyltrime1hoxysilane (MPS) c 3-glycidoxy-propyltrimethoxysilane (GPS)...

DNA immobilized by organosilane chemistries has proven to be an effective method for measuring impedance changes upon hybridization using both gold and platinum electrodes [21,50]. The effect of different silane chemistries creates differences in the hydrophobicity and hydration levels of the modified surface. The organosilane treatment along with the ssDNA... 

Flowever, the focus of the major part of the chapters lies on the couphng chemistry used for DNA immobilization. Successful immobihzation techniques for DNA appear to either involve a multi-site attachment of DNA (preferentially by electrochemical and/or physical adsorption) or a single-point attachment of DNA (mainly by surface activation and covalent immobihzation or (strept)avidin-biotin linkage). Immobilization methods described here comprise physical or electrochemical adsorption, cross-linking or entrapment in polymeric films, (strept)avidin-biotin complexation, a surface activation via self-assembled monolayers using thiol linker chemistry or silanization procedures, and finally covalent coupling strategies. 

Kumar A, Larsson O, Parodi D, Liang Z (2000) Silanized nucleic acids a general platform for DNA immobilization. Nucleic Acid Res 28 e71... 

Silanized Nucleic Acids a General DNA Immobilization Platform. 54... 

Fig. 1 Comparison of a conventional DNA-attachment scheme and the silanized nucleic acid strategy. A In conventional deposition methods the slides are universally coated with silane or poly-lysine, then oligonucleotides or cDNA is deposited on the modified surface. The areas on the chip that are not occupied with DNA will have to be blocked in hybridization experiments. B The DNA or oligonucleotides are modified with a silyl group that can directly immobilize the DNA onto an unmodified glass surface...

In our AFM-FS experiments of protein-DNA complexes, the respective DNA target sequences were covalently coupled to Si3N4 AFM cantilevers via monolayer activation and a functional heterobifunctional spacer molecule. The corresponding (His)6ExpG protein was immobilized on a silanized mica surfaces by a short linker molecule coupled to one of the five ExpG lysines. We used a commercial AFM instrument at 25°C that has been modified with a home-built electronics and data acquisition (Bartels et al. 2003). 

Scheme 4.1 Schematic illustration of DNA-dye-nanoprism cluster assembly. (A) Ag nanoprisms are immobilized on a silanized glass slide. (B) A ssDNA monolayer is attached to the nanoprisms via a S thiol group. (C) Complementary DNA conjugated with a fluorescent dye is hybridized to the DNA-frmctionalized nanoprisms, resulting in (D) specific attachment of the dye at a finite distance from the nanoprism surface. Reprinted from reference 9.

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