|Christof M. Niemeyer
Biologisch-Chemische Mikrostrukturtechnik, University of Dortmund, Otto-Hahn-Str. 6, D-44227 Dortmund, Germany
We have developed self-assembled oligomeric networks consisting of streptavidin (STV) and dsDNA, which are applicable as model systems for ion-switchable nanoparticle networks and nanometer-scaled "soft material" standards for scanning probe microscopy. Moreover, conjugates of single-stranded DNA and STV are being utilized as biomolecular adapters for the immobilization of biotinylated macromolecules at solid substrates via nucleic acid hybridization. This "DNA-directed immobilization" allows one for reversible and site-selective functionalization of solid substrates with metal and semiconductor nanoparticles, or, vice-versa, for the DNA-directed functionalization of gold nanoparticles with proteins, such as immunoglobulins and enzymes. This approach is applicable for the detection of chip-immobilized antigens. Moreover, the covalent DNA-STV conjugates allow for selective positioning of biotin-derivatized components along a single-stranded nucleic acid molecule. Examples include the fabrication of functional biometallic nanostructures from gold nanoparticles and antibodies, applicable as diagnostic tools in bioanalytics.