Switchable DNA layers as novel scheme in silicon nanowire based bio-sensing

• Applicant: Professor Dr. Marc Tornow
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 223745998

The central objective of the project is to realize a novel scheme in label-free biosensing based on silicon nanowires that are functionalized with switchable DNA molecules. Nanowire sensors are intensively investigated owing to their high relevance for applications in medical diagnostics and pharmaceutics. The basic detection principle relies on the semiconductor field effect. As major new component of the proposed project these wires shall be surface-functionalized with DNA molecules whose conformation can be electrically switched. By combination with this switching function we intend to demonstrate that the sensitivity for detecting biochemical binding reactions can be significantly enhanced. Our work shall concentrate on the detection of DNA hybridization as model system first. Following, the scheme can be extended towards other systems such as antibody-protein. The project in organized in four tasks: 1) Functionalization of silicon surfaces with DNA layers. 2) Controlled electrical switching of DNA on Si. 3) Transfer of the methodology to silicon nanowires. 4) Substantial enhancement of the device sensitivity by specific reduction of screening effects. The new scheme shall be tested by measuring DNA binding kinetics and affinities, and by determining the detection specificity down to single base-mismatches.

• DFG Programme: Research Grants