Objectives

In this project, we aim to combine the advantages of surface-enhanced Raman spectroscopy (SERS) and DNA origami to develop a new generation of biosensors, by extending existing concepts for nano-arrangements on DNA origami for SERS. We are aiming to create highly ordered 2D arrays from at least three nanoparticles (NPs) in order to create hot spots of defined quantities and local distribution in the light-exposed areas. In this way, we create the indispensable prerequisites for the quantification of an analyte. The additional positioning of the biological recognition element (bioRE) in the light-exposed hotspots of the NPs as the immobilization method enables the respective analyte to be detected qualitatively and quantitatively directly from a supernatant solution. In this way, a direct correlation between analyte concentration and the SERS signal could be analyzed.

The variability of the DNA origami as a binding matrix for various bioRE and NPs offers the possibility to construct individual structures and arrays, and to adapt them to the requirements of the measurement method. By integrating several heterogeneous bioRE (e.g. DNA probes), the additional function of multivalent binding of a target can be supplemented, so that the selectivity towards foreign bones within the analyte solution can be increased. In order to further increase the universal applicability of our sensor platform, we aspire a build-up on flexible substrates in addition to solid substrates by means of lipid-bilayers for a potential use in textiles or as a wipe test. 

The direct detection of the analyte from the solution and the transfer to application-related surfaces represent two essential steps for the further development of current research on SERS and DNA origami supported diagnostics, which will bring a market launch into the existing biosensor technology significantly closer. The detection of various model analytes with high research relevance such as interleukin-6, aflatoxin, cancer DNA and recombinant surface proteins of influenza is intended to verify the high application potential of our sensor platform in the point-of-care diagnosis. However, our research results should not only limit the application of the technology to sensors and medical technology, as application in optics or telecommunications also seem conceivable.

The mentioned research concept results in the following, overarching objectives of the project:

1. Establishment of DNA origami as “nano-breadboard” for biological recognition elements
2. Proof of signal enhancement through spatial alignment of biological recognition elements
3. Demonstration of detection of food contaminants and bio markers on the novel sensor platform 
4. Transfer of the sensor platform to a flexible substrate