Exploration of heat conductivity effects for applications in bio- and chemosensors (R-4206)

This project focuses on the 'heat-transfer effect' which was recently discovered by the applicants in the context of DNA-denaturation studies. Molecular brushes of double-stranded DNA, grafted on a temperature-controlled sensor electrode, do not measurably impede the transfer of thermal energy from the electrode to the electrolyte solution above the DNA layer. In contrast to this, single-stranded DNA acts as an efficient thermal insulator and the thermal resistance at the solid-to-liquid interface shows a substantial increase. This finding is not only surprising but it can also be utilized to identify DNA-melting temperatures in an uncomplicated way. These melting temperatures provide in turn information on the presence of single-nucleotide polymorphisms (small mutations), which are related to several hundreds of inherited health disorders. Preliminary studies have shown that heat-transfer effects also occur during other biological or chemical processes taking place at the interface between a solid support and an electrolyte: i) chemical denaturation of DNA, ii) absorption/desorption of protein layers, and iii) during the binding of small molecules (e.g. neurotransmitters) to molecularly imprinted polymers. Therefore, we propose that the heat-transfer resistance can be considered as a new, observable parameter in bio- and chemosensors. The project envisages as a first step the optimization of the sensor device in terms of maximizing the signal-to-noise level by modifications of the sensor design and the measuring methodology. Next, a detailed study will be performed on different interface-related biological- or chemical processes in order to verify the validity of the concept and to identify the magnitude of the associated heat-transfer resistance changes in a quantitative way. Finally, routes will be explored to translate the heat-transfer approach into an array format with parallelized measurements, being essential for many diagnostic- and genomic purposes.

Keywords:nanoparticles and -clusters

Disciplines:Medicinal and biomolecular chemistry, Molecular and cell biology, Plant biology, Systems biology, Ceramic and glass materials, Materials science and engineering, Semiconductor materials, Biophysics