Nanofluidic interconnects within a multilayer microfluidic chip for attomolar biochemical analysis and molecular manipulation

A multiple layer biochemical micro-analytical system has been developed that allows several functions to be conducted on mass limited (attomolar) samples of analytes that are in high backgrounds of constituent molecules. The functions are enabled by nanofluidic interconnects that join separate microfluidic channels, which carry various buffer solutions, reactants, and products of different composition, concentration, and pH. The microfluidic channels are separated in the vertical direction by membranes with nanometer diameter cylindrical pores that serves as the nanofluidic interconnect. The functions this multilayer, micro-nanofluidic chip can perform include: (1) standard electrophoretic separations; (2) injections of attoliters of solution from one microfluidic channel into another with near instantaneous mixing and reaction; (3) collection and manipulation of specific analyte bands; (4) molecular size/mass dependent selective gating; (5) rapid mixing and chemical reactions between separate microfluidic channels; and (6) controlled maintenance of specie concentration, salt, buffer, and pH gradients between microfluidic analysis channels.