TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: (M1) further involves selecting the edge of blocking mask for controlling light diffraction, where the blocking mask is formed of a material, which is opaque to light. The blocking mask is formed of a metal or aluminum foil. (M1) further involves developing the photoresist after the step of placing blocking mask over the photomask. The gradient interface region comprises several gradient structures, and a lateral distance between the gradient structures is decreased towards the nanofluidic region below 500 nm, preferably below 10 nm, or reduced to a distance substantially of a diameter of a biopolymer. The gradient structures have a gradual vertical elevation from the microfluidic region to the nanofluidic region, where the gradient structures are branched channels. The gradient interface provides a gradual increase in vertical elevation from the microfluidic region to the nanofluidic region. The steps of forming the gradient interface region and the microfluidic region are formed simultaneously by carrying out coating photoresist over the substrate, providing a photomask over the photoresist, where the photomask patterns the microfluidic region and the gradient interface region, providing a blocking mask over the photomask, where the blocking mask extends over a portion of the photomask applied over the nanofluidic region and exposing the photomask to light. The photomask has a thickness in a range of 1 mm to 10 mm and the blocking mask has a thickness in the range of 1 mm to 12 mm. The step of providing a blocking mask over the photomask further involves controlling a distance between the blocking mask and the photomask, where the distance controls an amount of light diffraction along an edge of the blocking mask. The nanofluidic region comprises a nanofluidic structure chosen from nanopillars, nanopores and nanochannels, which are formed by nanoimprint lithography, interference lithography, self-assembled copolymer pattern transfer, spin coating, electron beam lithography, focused ion beam milling, photolithography, reactive ion-etching, wet-etching, plasma-enhanced chemical vapor deposition, electron beam evaporation, sputter deposition, and their combinations. In (M2), the step of coating photoresist on (II) further involves providing a photomask over the photoresist, where the photomask patterns the microfluidic region and the gradient intersurface region. The blocking mask is coated on the photoresist. (III) further comprises a unit for developing the photoresist. The gradient structures have a gradual vertical elevation from (II) to the nanofluidic region. The unit for forming a gradient interface region comprises a unit for applying photoresist over (II), unit for applying a photomask over the photoresist, unit for providing a blocking mask over the photomask, where the blocking mask extends over a portion of the nanofluidic region, and a unit for exposing the photomask to light. In (IV), the gradient intersurface region comprises branched fluidic channels having reduced lateral distance between adjacent channels toward the nanofluidic region. In (M3), the detected signal is correlated to any one of the properties such as length, conformation, physical and chemical attachment such as a bound marker or tagging and chemical composition. The biopolymer is a protein, a polypeptide or a nucleic acid, where the nucleic acid is DNA and the detected signals are correlated to the base pair sequence of the DNA. The biopolymers are substantially unfolded in the channels. The concentration of the macromolecules in the fluid is 1 attogram/ml, 1 femtogram/ml, 1 picogram/ml or the concentration is less than 5 mug/ml or preferably less than 0.5 mug/ml. The macromolecules have elongated length in the channels of greater than 500 nm, 1 micron or 10 microns. The macromolecules are DNA having greater than 1000000, 100000, 10000, 1000 or 100 base pairs. A macromolecule is a chromosome which is analyzed to determine the presence of a single nucleotide polymorphism. EXAMPLE - No relevant example is given.