Nano-sieve efficiently captures and releases tiny bioparticles

Rapidly isolating and retrieving small molecules from large volumes of solutions is crucial for many clinical and environmental applications, including disease diagnosis, cell biology, therapeutics, and water purification. While selective nanofiltration membranes are low cost and easy to use, post-treatments are needed to retrieve the tiny molecules. Electrophoresis helps with this separation, but the DC current required for this process can change the electrostatic force in the solution.

Nanaware et al. developed a nano-sieve capable of efficiently capturing and retrieving nanoparticles with a size of only 15 nanometers.

The sieve contains deformable microgrooves which serve to channel the fluid while control the flow rate and capture efficiency. Because of the high flow rate within the nano-sieve, the researchers found it necessary to counterbalance the hydrodynamic pressure with a pneumatic chamber added on top of the device.

“The target capture can be enhanced by adding a positive pressure on the pneumatic layer,” said author Ke Du. “By switching to negative pressure, the captured targets can easily be retrieved for downstream analysis.”

By manipulating different physical properties, such as channel height and flow rate, the system can be tuned to separate various sized nanoparticle targets from the same sample.

“Our work is a major step forward in the field of nanofluidic size exclusion as our channel height can be precisely controlled to fit different applications,” said Du.

Future work with the pneumatic system will focus on separating biological materials of similar size, such as extracellular vesicles, proteins, and nucleic acids.

Source: “Pneumatic controlled nanosieve for efficient capture and release of nanoparticles,” by Animesh Nanaware, Taylor Kranbuhl, Jesus Ching, Janice S. Chen, Xinya Chen, Qingsong Tu, and Ke Du. The article can be accessed at https://doi.org/10.1116/6.0002107 .

This paper is part of the Papers from the 65th International Conference on Electron, Ion, And Photon Beam Technology and Nanofabrication (EIPBN 2022) Collection, learn more here .