Zhejiang University: 2D sieving structure for DNA sequencing

Two-dimensional (2D) nanomaterials exhibit immense promise in such fields as biosensing and medicine. The state-of-the-art nanofabrication technology has enabled the integrated in-plane growth of 2D hetero-nanostructures, such as graphene and hexagonal boron nitride. The flexible nature of this lateral hetero-nanostructure opens the door to the innovative design of single-molecule biological devices.

On July 14, the research team led by Prof. ZHOU Ruhong from the Zhejiang University Institute of Quantitative Biology published a research article entitled “Exploring an In-Plane Graphene and Hexagonal Boron Nitride Array for Separation of Single Nucleotides” in the journal ACS Nano. In this study, researchers proposed an in-plane array based on graphene and hexagonal boron nitride and explored its potential for DNA sequencing.

Using all-atom molecular dynamics simulations, researchers found that due to the difference in adsorption capacity between graphene and hexagonal boron nitride, a nucleotide encounters a size-dependent periodic barrier when traveling across the alternating graphene and hexagonal boron nitride stripe driven by an electric field. This periodic potential barrier can modulate the movement of different types of mononucleotides on the 2D surface, resulting in their different velocities and directions of motion even in the same electric field and eventually the successful separation of different types of single nucleotides. Furthermore, researchers also discovered that the velocity modulation is particularly sensitive when the sample dimension is within the range from half a period to a full period of the nanoarray.

In comparison with the traditional gel electrophoresis separation technique, this 2D nanofluidic sieve is marked by its remarkable speed and sensitivity. Moreover, it is more easily integrated into nanofluidic chips because it doesn’t require gel as a separation medium. This 2D sieving structure may shed light on the development of lab-on-a-chip sequencing in the future.