Gradient structures interfacing microfluidics and nanofluidics

A fluidic chip for detecting a property of a macromolecule, comprising:

• a substrate into or on which are superposed:
• at least one array of nano scale fluidic structures having a lateral spacing distance between 2 nm to 200 nm and being capable of communicating fluid therethrough, such that at least one property of a macromolecule can be detected when the macromolecule is positioned within or passes through the array of nanoscale fluidic structures;
• a plurality of microfluidic structures having a lateral spacing distance between 0.5 microns to 5 microns and being capable of communicating fluid therethrough;
• a gradient interface capable of communicating fluid between the plurality of microfluidic structures and said nanoscale fluidic structures, said gradient interface characterized as having a cross-sectional area, and comprising (a) a plurality of lateral spatial gradient structures therein, wherein the lateral spacings between said gradient structures increase when proximal or adjacent to the at least one microfluidic structure than are the lateral spacings proximal or adjacent to the array of nanoscale fluidic structures, or (b) a vertical slope, such that the vertical spacing proximal or adjacent to the at least one microfluidic structure is increased than is the vertical spacing proximal or adjacent to the array of nanoscale fluidic structures, or (c) both (a) and (b), such that the gradient interface provides for a narrowing of the cross-sectional area of the fluidic structures adjacent to the at least one microfluidic structure to the fluidic structures adjacent to the nanoscale fluidic structures.