Diamond-based impedimetric and nanophotonic biosensors for the detection of proteins (R-2845)

This project aims at the development of biosensors for the detection of medically relevant proteins in matrix materials like blood serum. The detection will be based on two complementary, label-free methods: i) impedance spectroscopy is an established electronic approach, while ii) nanophotonics is a very recent evolution. Both technologies employ synthetic diamond layers, patterned down to nanostructured leads and waveguides, which serve at the same time for electronic- and optical sensing purposes. The choice for diamond coatings, in essence a cheap product and technically speaking a wide-bandgap semiconductor, is made for their excellent thermal and chemical stability. Moreover, synthetic diamond allows for the covalent attachment of receptor molecules, e.g. by photochemical methods, and has in addition biocompatible properties. The receptor molecules are immunoglobulins, the classical approach in protein sensing, and in addition also aptamers are employed. These are novel, synthetic receptors with appealing properties concerning synthesis and long-term stability. Due to the miniaturized size of the nanophotonic and impedimetric sensors and sensor arrays, we make a twofold use of continuous and digital microfluids: to load the sensors with receptors and also to bring analytes, such as serum droplets, in a targeted way to the sensor spots. We aim at detection limits in the physiologically relevant nanomolar concentration range.

Keywords:biosensors, impedance spectroscopy, microfluidics, protein detection, synthetic diamond

Disciplines:Physical sciences, Materials engineering