Chemists at Johannes Gutenberg University Mainz (JGU) have developed a new method for parallel protein analysis that is, in principle, capable of identifying hundreds or even thousands of different proteins. It could be used to detect the presence of viruses and identify their type in tiny samples. At the same time, it is very cost-effective and quick. "We see possible applications of this technique in medicine, where it could be used, for example, for the rapid diagnosis of a wide range of diseases. It would be almost as easy to use as a pregnancy test strip," said Professor Carsten Snnichsen of the Institute of Physical Chemistry. The test involves placing a tiny drop of blood, saliva, or other bodily fluid on a small test strip, which is then placed in a device developed at the JGU Institute of Physical Chemistry. This device is able to identify the specific proteins in the fluid and thus allows to quickly and reliably differentiate between harmless microorganisms and dangerous pathogens.
In order to detect the many different substances present in a small sample, the sensors need to be as tiny as possible, preferably the size of nano-particles. Snnichsen's team of scientists have designed a sensor no larger than the head of a pin but capable of performing a hundred different individual tests on a surface that is only of one-tenth of a square millimeter in area. The 'test strips' consist of glass capillary tubes that have gold nano-particles as sensor elements on their internal surfaces. "We first prepare our nano-particles using short DNA strands, each of which binds to a specific type of protein," explained Janak Prasad, who developed the functionalization method. When a protein docks with one of these special DNA strands, called aptamers, the corresponding nano-particle changes its color. The color changes can be detected with the aid of a spectrometer. For this purpose, the capillary tubes are placed under a microscope designed, constructed, and
|Contact: Dr. Carsten Sönnichsen|
Johannes Gutenberg Universitaet Mainz