Regenerative Acoustofluidic NanoFilters for Biomolecular Purification and Quantification

Precise manipulation of target molecules is critical for microfluidic applications, such as molecular purification, target enrichment, and biosensing. Here, we report a microfluidic-based regenerable nanoscale filtration technique for purification and detection of target molecules from complex samples. By assembling specific functionalized nanoparticles (SFNPs) in an acoustofluidic vortex chip, an array of nanofilters is constructed. The acoustofluidic vortex is produced by a gigahertz bulk acoustic wave resonator, which allows for simple regeneration. Additionally, the acoustofluidic vortex increases SFNP–target interactions, overcoming diffusion limits. We demonstrate this nanofiltration method for rapid and effective purification of targets in both buffer and serum samples. We studied the molecular capturing dynamics using the biotin-SAv complex as a model, where we demonstrate a rapid (within 60 seconds) and accurate (with a detection limit of 170ng/mL) molecular quantification biosensor. The approach has the advantages of non-clogging high-throughput capability, as well as excellent flexibility, enabling wide biomedical applications.