Bioselective agglutination induced nanoscale deterministic lateral displacement

Nanoscale deterministic lateral displacement (nanoDLD) is a microfluidic-based size separation technique allowing separation of subcellular biological particles such as double-stranded DNA and extracellular vesicles. Although there has been extensive study of the separation mechanism, across several applications, a systematic study of migration angle shift due to aggregation has not been done. A bead-based immunoassay is developed to aggregate and separate in the presence of a target protein. The results show that the system effectively separates particles, shows bioselectivity, and allows for the detection of target proteins. We demonstrate the agglutination model can be used to explain the migration angle of the aggregation process as a function of antibody and antigen concentrations.