2D crystalline protein layers as immobilization matrices for the development of DNA microarrays.
There is a growing demand for functional layers for the immobilization of (bio)molecules on different kinds of substrates in the field of biosensors, microarrays, and lab-on-a-chip development. These functional coatings should have the ability to specifically bind (bio)molecules with a high binding efficiency, while showing low unspecific binding during the following assay. In this paper we present rSbpA surface layer proteins (S-layer proteins) as a versatile immobilization layer for the development of DNA microarrays. S-layer proteins show the ability to reassemble into two-dimensional arrays on solid surfaces and their functional groups, such as carboxylic groups, are repeated with the periodicity of the lattice, allowing for immobilization of other (bio)molecules. Different fluorescently labeled amino functionalized DNA oligomers were covalently linked to the S-layer matrices to allow the characterization of DNA binding on S-layers. Hybridization and dissociation of DNA-oligomers were studied on S-layer coated slides, revealing low levels of unspecific adsorption of DNA on S-layer based immobilization matrices. In the following the principle was transferred to a DNA microarray design showing successful spotting and hybridization on whole microarray slides. Besides common laser scanning for fluorescence detection, S-layer based microarrays were evaluated with a compact, low cost platform for direct fluorescence imaging based on surface plasmon enhanced fluorescence excitation. It could be shown that S-layer protein layers are promising as immobilization matrices for the development of biosensors and microarrays.
Joanneum Research, Institute of Surface Technologies and Photonics, Steyrergasse 17, Graz 8010, Austria. sylvia.scheicher@joanneum.at
Sylvia R
SR
Scheicher
Birgit
B
Kainz
Stefan
S
Köstler
Norbert
N
Reitinger
Nicole
N
Steiner
Harald
H
Ditlbacher
Alfred
A
Leitner
Dietmar
D
Pum
Uwe B
UB
Sleytr
Volker
V
Ribitsch
D015374:Biosensing Techniques / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D004247:DNA / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008562:Membrane Glycoproteins / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D011485:Protein Binding; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
D020099:Coated Materials, Biocompatible; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D004247:DNA