Nanoscale analysis with DNA-graphene origami

November 29, 2024

In a recently published study in Advanced Materials Interfaces, INL researchers have developed a new sensor that merges DNA origami with graphene to achieve unique accuracy in detecting molecular motion. Nieder’s group at INL, together with Alpuim’s group (INL) and Thorsten-Lars Schmidt  (Kent State University), developed this innovative sensor that could have significant potential for applications in medicine and environmental monitoring.

The sensor combines DNA origami structures and a graphene layer functionalised to interact with fluorescent markers. These markers emit light, and their fluorescence behaviour – specifically its duration – changes based on their proximity to the graphene. By applying electrical signals, researchers can control this distance, enabling them to track movements as small as two nanometres.

“The novelty here is that we can actually gate the graphene and sense the effects of this electrostatic approach in the fluorescent behaviour of the fluorophores,” explains João Azevedo, first author of the study.

The team used Fluorescence Lifetime Imaging Microscopy (FLIM), a technique that measures the time fluorescence lasts, to achieve this high-resolution sensing. Unlike traditional fluorescence intensity methods, FLIM is less affected by photobleaching, a process where fluorescent markers lose their ability to emit light after prolonged exposure. By focusing on lifetime rather than brightness, the sensor provides more reliable data for an analysis at the nanoscale.

“What we were able to achieve in this interdisciplinary team was to use a 2D material functionalised substrate together with the DNA origami structure, to create molecular motions on demand,” says Jana Nieder, research group leader at INL and coordinator of the study. “This level of control on the molecular scale might be relevant for future bio-sensing applications.”

This technology combines the precise nanoscale design capabilities of DNA origami with the conductive and versatile properties of graphene. The researchers see a wide range of potential uses for their sensor, such as detecting specific proteins, studying cell mechanics, or even diagnosing diseases. All of these with minimal invasiveness and high accuracy.

As nanotechnology continues to advance, innovations like this DNA-graphene hybrid sensor, developed under the project ON4SupremeSens, are bringing us closer to a future where even the tiniest biological interactions can be observed and understood.

Text by Catarina Moura
Photography & Videography by Catarina Moura & Rui Andrade
Digital media edition by Rui Andrade