Catching and releasing tiny molecules

Employing an ingenious microfluidic design that combines chemical and mechanical properties, a team of Harvard scientists has demonstrated a new way of detecting and extracting biomolecules from fluid mixtures. The approach requires fewer steps, uses less energy, and achieves better performance than several techniques currently in use and could lead to better technologies for medical diagnostics and chemical purification.

The biomolecule sorting technique was developed in the laboratory of Joanna Aizenberg, Amy Smith Berylson Professor of Materials Science at Harvard School of Engineering and Applied Sciences (SEAS) and Professor in the Department of Chemistry and Chemical Biology. Aizenberg is also co-director of the Kavli Institute for Bionano Science and Technology and a core faculty member at Harvard’s Wyss Institute for Biologically Inspired Engineering, leading the Adaptive Materials Technologies platform there.

The new microfluidic device, described in a paper appearing today in the journal Nature Chemistry, is composed of microscopic “fins” embedded in a hydrogel that is able to respond to different stimuli, such as temperature, pH, and light. Special DNA strands called aptamers, that under the right conditions bind to a specific target molecule, are attached to the fins, which move the cargo between two chemically distinct environments. Modulating the pH levels of the solutions in those environments triggers the aptamers to “catch” or “release” the target biomolecule.