Ribbon Reading

Scientists from the Laboratory of Nanoscale Biology at École Polytechnique Fédérale de Lausanne (EPFL) have created a model for reading DNA, which will detect passage of individual DNA molecules through a nanopore. The new system is an improved version based on a method known for over a dozen years.

In this method, the DNA molecules are diluted in a solution containing ions and are driven by an electric field through a membrane with a nanopore. When a molecule passes through the orifice, a slight perturbation is provoked in the field, which can be detected by modulations in ionic current and by concomitant modulation in the graphene transistor current. Through this information, it can be determined whether a DNA molecule has passed through the membrane or not.

The earlier method lacked precision and led to the clogging of nanopores. Scientists overcame these shortcomings by using graphene as it is thin and yet, extremely resilient. Strips of graphene or nanoribbons produced at EPFL coincidently fit in the gap between the two DNA bases. As a result, a much higher precision is possible at analysing these DNA bases.