Zero-mode waveguides with non-reflecting walls
The application relates to improved optical containment structures, methods of manufacture and use, and systems for employing same. The optical containment structures generally comprise zero-mode waveguide structures having non-reflective walls. The non-reflective walls allow the preparation of optical containment regions in which the optical containment dimensions can be decoupled from the solution containment dimensions. The application also relates to methods for producing islands of functionality within nanoscale apertures.
1. A zero-mode waveguide structure comprising:
a) a transparent substrate having a top surface;
b) an opaque layer comprising a metal disposed upon the top surface of the transparent substrate;
c) an array of apertures extending through the opaque layer to the transparent substrate whereby the apertures comprise wells having walls and bases, the bases of the wells comprising portions of the top surface of the transparent substrate; and
d) a non-reflective layer comprising an oxide formed by oxidation of the metal disposed on the walls of the wells wherein the thickness of the non-reflective layer is greater than about 10 nm.
2. The zero-mode waveguide of claim 1 wherein the opaque layer comprises aluminum, and the non-reflective layer comprises aluminum oxide.
3. The zero-mode waveguide structure of claim 1 wherein the apertures comprise cylinders.
4. The zero-mode waveguide structure of claim 1 wherein the apertures comprise conical structures.
5. The zero-mode waveguide structure of claim 1 wherein the thickness of the non-reflective layer is greater than about 10% of the largest cross-sectional dimension of the wells.
6. The zero-mode waveguide of claim 5 wherein the wells comprise cylindrical structures, whereby the largest cross-sectional dimensions comprise the diameters of the cylinders.
7. The zero-mode waveguide structure of claim 1 wherein the solution volume of the zero-mode waveguide is less than about 80% of the ZMW volume of the zero-mode waveguide.
8. The zero-mode waveguide structure of claim 1 wherein the aperture has a solution cross-sectional area and a ZMW cross-sectional area, wherein the solution cross-sectional area is less than about 80% of the cross-sectional area of the zero-mode waveguide.
9. An apparatus for obtaining nucleic acid sequence information comprising:
a) a zero-mode waveguide array structure of claim 1 ; the zero-mode waveguide structure in contact with an analysis solution, whereby the wells comprise the analysis solution which comprises reagents for carrying out reactions for which nucleic acid sequence information can be derived; including polymerase enzyme, nucleotides, and nucleic acid template, the solution further comprising fluorescent species;
b) an excitation illumination source that illuminates the wells through the transparent layer;
c) a detector array that detects emitted light over time from the fluorescent species within the wells, wherein the emitted light passes through the transparent layer; and
d) a computer that analyzes the emitted light over time in order to obtain sequence information.