Some of our projects

Back Scattering Interferometri – a new optical in situ method for complete analysis of cardiac markers

The approach is to include all measurements on a multiple microfluidic channel platform, thus making it an ideal detector for the proposed complete analysis of the cardiac markers in the blood in patients with acute coronary syndromes, e.g., unstable angina pectoris or acute myocardial infarction.

The novelty in the proposed project is the ability to analyze several mixtures of various concentrations with a known concentration of a third analyte on a single chip in near real-time.  This embodiment allows binding assays to be done on a single device in a completely label-free format with just nanoliter volumes. Back Scattering Interferometri, an optical technique, can detect minute changes in refractive index at the 10-9 level in ultra small volumes in situ. Protein binding interactions can be non-invasively monitored on-chip, in free solution, and in real-time using Back Scattering Interferometri.

Back Scattering Interferometri has high sensitivity with detection limits in the low attomole range of proteins like human IgG, corresponding to improved sensitivity five orders of magnitude better than commercially available equipment. This optical method has been developed jointly by the DTU Fotonik and Vanderbilt University groups, which also share joint patents on this technique. In the long term perspective, applying this novel diagnostic tool to coronary artery disease, earlier and better monitoring of patients will potentially reduce the number of deaths, facilitate early risk stratification (e.g., for selection of patients most likely to benefit from high-cost invasive treatment), and hereby improve the life quality of patients.

Micromaterials acting as sensor layer

There is a high need for wear indications of tribological layers for tools that are used in industrial production lines. If a tool is worn out without notice, it means delay in the production or exchange of expensive parts. DTU and the company CemeCon Scandinavia A/S has therefore attempted to include a warning layer which can be detected optically in collaboration with University of Copenhagen and Ecole-Centrale Lyon.

The idea is to include an optical warning layer of about 100 nm TiN in the tribological coating of TiAlN which is about 3 micrometer thick. The reflectance from TiN is high compared to the reflectance from TiAlN, so when the reflection increases drastically, the user knows that the TiAlN coating is depleted leaving the remaining TiN layer visible. The sensor device can be a cheap, simple red diode laser directed remotely on the tribological coating.

DTU Fotonik also has the possibility of producing thin layers of these coatings with pulsed laser deposition (PLD) in collaboration with Risø DTU’s Department of Fuel Cells and Solid State Chemistry. Pulsed laser deposition is a technique for thin film production by which the stoichiometry of the film is similar to the target material, even for very complex materials, e.g.oxides.