Master of Layers
Surflay Nanotec develops nanometre-thin coatings that serve as biosensors and contribute to keeping Berlin’s water clean
At first glance, the labs at Surflay Nanotec look like just like any other lab: ventilation, centrifuges, pipettes, and microscopes. Then you stumble upon a shelf that looks like it might belong in a barber shop. There are mannequins wearing multi-coloured toupees with various highlights taped to a white strip. They are part of a project that the company founder Lars Dähne loves to tell people about: “We developed a procedure for a cosmetics company that facilitates colouring and decolouring hair.” All thanks to a nanocoating that is the specialty of his company.
“The procedure is basically quite simple,” says the PhD chemist and slaps his hand on the table. “The surface of this table has more negative than positive charge. If I add polymers with a positive charge, they attach themselves to the surface until it is full. This creates an additional layer that is only a few nanometres thick – a millionth of a millimetre – and a new surface with a positive charge.” Using this method, it is possible to add many layers, alternating between negative and positive charges, which is why the procedure is called “layer by layer”, or LbL. In 1998, researchers from the Max Planck Institute of Colloids and Interfaces in Potsdam successfully applied LbL to nanospheres. Lars Dähne was one of them. He then founded a company with colleagues that started out focusing on pharmaceutical applications. After realigning the company, he started again as Surflay Nanotec and focused on technical coatings in 2008.
“We don’t manufacture complete products with our team of 13 employees, we develop new procedures in the context of industrial or funding projects,” says Dähne. This includes a cooperation with Berliner Wasserbetriebe, Berlin’s public water supplier, who is facing issues with sulphates in Müggelsee lake and expect them to spread to the drinking water supply. To safeguard the quality of Berlin’s water, Surflay Nanotec is now researching custom coatings for membrane filters to repel sulphates and other substances.
A procedure for testing antibodies using light waves is another project that he is particularly attached to. Antibodies are bringing great hopes for cancer treatment and research is being encouraged on a global scale. They are used to “sharpen” the body’s defensive systems, getting the immune system to seek and destroy cancer cells. “When developing new therapies, it is crucial to carefully test the effect of antibodies on biological systems,” says Dähne. There are devices to do this that are based on surface plasmon resonance technology. They send light waves across samples and, by recording frequency changes, capture to what extent and how quickly the antibodies bind with antigens. However, this method is fairly expensive. Dähne is convinced that he can find a simpler and more cost-effective way. He uses coated polymer spheres, only a hundredth of a millimetre small, and “locks” light into them. Again, the aim is to examine changes in wavelength to gain insight into the antibodies” behaviour. This technology is called “whispering gallery modes.”
“We have developed the method, the particles, and the corresponding test device together with the physicist Michael Himmelhaus. The device fits on a table and can be transported in regular-sized car boot,” says Dähne, “and it works!” The company is currently working on building a demonstration model which will go on a tour of China in the following months – where it will hopefully lure in new customers.
By Ralf Nestler for Adlershof Journal