Arrays of integrated analytical devices and methods for production

A method of nucleic acid sequencing comprising the steps of:

• providing an array of integrated analytical devices, wherein at least one integrated analytical device in the array of integrated analytical devices comprises a nucleic acid template/polymerase primer complex immobilized within an optically confined region, a plurality of fluorescently labeled nucleotides in fluid contact with the nucleic acid template/polymerase primer complex, and a single detector element optically coupled to the optically confined region, wherein the optically confined region is in a nanowell that is illuminated by an optical excitation waveguide, and wherein at least two fluorescently labeled nucleotides of the plurality of fluorescently labeled nucleotides emit fluorescence of different intensities at an emission wavelength;
• illuminating the optically confined region with an excitation wavelength;
• measuring a fluorescent signal from the optically confined region at the single detector element;
• and
• identifying at least one of the at least two fluorescently labeled nucleotides by an intensity of the measured fluorescent signal at the emission wavelength.