By using biochips, even the smallest traces of organic molecules can be detected – for example, to search for toxins in foods. Yet the production and handling of sensors is costly.
How biochips be made easier to use?

Rainer Hintsche, Walter Gumbrecht, and Roland Thewes have found an answer to this question with their invention of a technology that combines biological elements with microelectronic components on the chip. Rainer Hintsche heads the group for biotechnical microsystems at the Fraunhofer Institute for Silicon Technology IST in Itzehoe; Walter Gumbrecht is project manager for the electrical Lab-on-a-Chip systems at Siemens Corporate Technology in Erlangen, Roland Thewes is responsible for R&D projects on CMOS-based biosensors at Infineon Technologies in Munich.

Using a biochip, biomolecules such as nucleic acids or proteins, can be traced in watery solutions. According to the lock-and-key principle, biomolecules anchored on the chip – so-called catchers – accurately bind certain other molecules. This produces a highly sensitive sensor for DNA or proteins. Reading of the results with a light beam, however, has usually been technically complex and expensive.

The three researchers succeeded in replacing this method with a considerably simpler and cost-efficient technology. In this case, the results are read on the chip by means of electrical measurements. The basis for this method is the discovery that as soon as it has found its counterpart, a catcher molecule emits an electrical signal which can be directly analyzed.

The measuring principle developed by Hintsche at IST underwent further development in collaboration with Siemens and Infineon directed by Gumbrecht and Thewes. The goal was to design sensor systems that are both economic and efficient and capable of being manufactured on a large scale for use as miniature labs. The systems first become a “Lab-on-a-Chip” when liquids and reagents are applied to the sensor surfaces. The entire innovation consists of a combination of silicon chip technology, biotechnology, and miniaturized fluidic technology.

The researchers laid the foundation for minute, portable, and at the same time, robust analysis systems in credit-card format. Cost-efficient laboratory diagnostics and rapid on-site analysis, for example, to detect toxins, are possible with the “Lab-on-a-Chip” as is individual analysis to measure a patient’s values. The principle of the electric biochip can be applied both in food analysis, pharmaceutics, as well as in agricultural and environmental analyses. The prize winners have over 50 patents on their inventions.