Illumination of integrated analytical systems
An analytical device including an optically opaque cladding, a sequencing layer including a substrate disposed below the cladding, and a waveguide assembly for receiving optical illumination and introducing illumination into the device. The illumination may be received from a top, a side edge, and a bottom of the device. The waveguide assembly may include a nanoscale aperture disposed in the substrate and extending through the cladding. The aperture defines a reaction cell for receiving a set of reactants. In various aspects, the device includes a sensor element and the illumination pathway is through the sensor element. Waveguides and illumination devices, such as plasmonic illumination devices, are also disclosed. Methods for forming and operating the devices are also disclosed.
1. A system for sequencing a nucleic acid, the system comprising:
an integrated analytical device comprising:
an optically opaque layer having a plurality of nanoscale apertures extending therethrough into a transparent substrate below the opaque layer, wherein the nanoscale apertures each define a reaction cell, wherein the reaction cells are configured to receive a nucleic acid sequencing reaction mixture comprising a plurality of fluorescently labeled nucleotides each having a different excitation spectrum;
a waveguide layer below the reaction cells comprising a plurality of waveguides each directing pulsed excitation light to multiple reaction cells; and
a detection layer below the waveguide layer comprising a plurality of sensor elements in optical communication with the reaction cells, wherein each reaction cell has at least one sensor element associated with it, wherein each sensor element comprises a pixel having multiple integrated storage elements, wherein the sensor elements detect optical signals emitted from the fluorescently labeled nucleotides; and
a light source that provides the pulsed excitation light to the waveguide layer of the integrated analytical device, the pulsed excitation light comprising pulses of at least two different excitation wavelengths that are delivered iteratively over time, wherein one of the at least two excitation wavelengths corresponds to the excitation spectrum of one fluorescently labeled nucleotide, and another of the at least two excitation wavelengths corresponds to the excitation spectrum of another fluorescently labeled nucleotide in the plurality of fluorescently labeled nucleotides;
wherein for each respective reaction cell and a corresponding sensor element, optical signals from the one fluorescently labeled nucleotide is stored in one of the multiple integrated storage elements of the pixel, and optical signals from the another fluorescently labeled nucleotide is stored in another of the multiple storage elements of the pixel, thereby distinguishing signals from different fluorescently labeled nucleotides.
2. The system of claim 1 , wherein the plurality of fluorescently labeled nucleotides comprise four fluorescently labeled nucleotides.
3. The system of claim 1 , wherein a single sensor element is associated with each reaction cell.
4. The system of claim 1 , wherein four sensor elements are associated with each reaction cell.
5. The system of claim 1 , wherein the pixel comprises four integrated storage elements.
6. The system of claim 1 , wherein each of the storage elements is electronically gated by the activation of a separate excitation source.
7. The system of claim 1 , wherein the analytical device further comprises a modulated controller element coupled to both the detector layer and the waveguide layer to synchronize illumination and storage.
8. The system of claim 1 , wherein a delay between an excitation event and an emission event for each label is preprogrammed into the sensor elements.
9. The system of claim 1 , wherein the sensor elements comprise a CMOS, NMOS, or PMOS sensor.
10. The system of claim 1 , wherein the plurality of sensor elements is between about 1,000,000 and 10,000,000 sensor elements.
11. The system of claim 1 , wherein the reaction cells comprise zero mode waveguides.
12. The system of claim 1 , wherein the analytical device further comprises a fluidic conduit that extends across multiple reaction cells.
13. The system of claim 1 , wherein the analytical device further comprises a transmission layer between the waveguide layer and the detector layer that transmits emitted light from the reaction cells to the detector layer.
14. The system of claim 13 wherein the transmission layer comprises an optical tunnel.
15. The system of claim 13 wherein the transmission layer comprises optical filters.
16. The system of claim 1 , wherein each integrated storage element is an integrating node, wherein the integrating nodes are independently reset to clear previous charges from their circuits prior to transfer operations.