Protein Assisted DNA Monolayer Assembly (UKF 22/08)

FAU-externes Projekt

Details zum Projekt

Prof. Dr. Ana-Suncana Smith

Beteiligte FAU-Organisationseinheiten:
Professur für Theoretische Physik

Mittelgeber: FWF. Der Wissenschaftsfonds (The Unity Through Knowledge Fund)
Projektstart: 01.09.2008
Projektende: 31.08.2010

Abstract (fachliche Beschreibung):

Rapid detection of specific DNA sequences, so-called DNA-sensing, has important technological applications, but also raises several fundamental questions in the field of biophysics. Studies of DNA sensing are very widespread and intense, and instead of performing the tests by time consuming methods in solutions, today’s methods concentrate on immobilization of DNA probes on substrates – i.e. on massive parallel processing of target molecules on DNA sensors/chips. However, the feasibility and speed of processes occurring on these sensors are highly dependent on the accessibility of the genetic code, which is itself determined by the conformation of the DNA molecule on the surface. We here propose to develop a novel array of fully extended, hence fully accessible, DNA molecules which will enable us to overcome some of the important limitations of previously designed sensors. Developing such an original approach, is a feat in itself, but is nevertheless necessary in order to give us a competitive edge. Successful accomplishment will provide us with a solid groundwork for studies of specific DNA interactions in two-dimensional geometries as well as direct us toward exploring possibilities for technological innovations. We intend to utilize in a rather original manner the natural functional structure of DNA and RecA protein complexes – nucleoprotein filaments. We propose that it is possible to attach DNA molecules to the substrate in a uniform and organized way, while forming nucleoprotein filaments which have a large persistence length. Thus we expect to obtain a self-assembled monolayer of densely packed rod-like nucleoprotein filaments in “brush”-like conformation. Both, single or double stranded DNA probes, with much larger range of lengths will be used as probes, thus providing a single flexible approach to DNA sensor preparation. The research of the formation of such a layer will also give insight into fundamental concepts of charged polymers like coil-globule and/or brush-mushroom transition or the persistence length in restricted 2D geometry. This work is based on the team’s complementary experience with DNA/RecA complexes preparation, chemistry of DNA/substrate interactions, impedance spectroscopy and nonlinear laser optics for detection, as well as on the expertise in modeling of soft-matter interfaces. An essential step of the current project is the construction of a 2-photon absorption fluorescence correlation spectroscopy instrument that can detect the anticipated low DNA-target/probe concentration-changes in a most precise manner. Beyond the direct scope of the current proposal, but as its consequence, the scientific community in Croatia will have direct access to this advanced technique.


Fenz, S.F., Smith, A.-S., Merkel, R., & Sengupta, K. (2011). Inter-membrane adhesion mediated by mobile linkers: Effect of receptor shortage. Soft Matter, 7(3), 952-962.

Zuletzt aktualisiert 2018-19-12 um 08:41