title: Continuous-flow biomolecule concentration and detection in a slanted nanofilter array.
abstract: We demonstrate continuous-flow biomolecule concentration and detection in a microfabricated slanted sieving structure, which we term a herringbone nanofilter array (HNA). The HNA structure consists of periodically-patterned deep and shallow nanoslits meeting at right angles. In addition to concentration, we can discriminate different sized analytes by mixing a fluorescent probe with the sample and measuring the extent of the concentrating effect. Using this principle, we interrogate biomolecular interactions, including protein-DNA binding, protein-protein interaction and antibody-antigen binding. The final example demonstrates a novel method to perform a homogeneous immunoassay for detecting a disease marker, human C-reactive protein (CRP), using fluorescent-labeled antibodies at clinically relevant concentrations. The signal amplification potential and continuous flow operation provide a significant advantage over other microfluidic batch separation techniques for the easy integration of this device into a common point-of-care diagnostic platform.
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Lih
authors.initials: L
authors.lastname: Feng Cheow
authors.forename: Hansen
authors.initials: H
authors.lastname: Bow
authors.forename: Jongyoon
authors.initials: J
authors.lastname: Han
mesh_terms: D000906:Antibodies / Q000032:analysis*; D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis*; D004247:DNA / Q000032:analysis*; D005453:Fluorescence; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*
chemical_list: D000906:Antibodies; D000941:Antigens; D002097:C-Reactive Protein; D004247:DNA