Arrays of integrated analytical devices and their methods for production are provided. The arrays are useful in the analysis of highly multiplexed optical reactions in large numbers at high densities, including biochemical reactions, such as nucleic acid sequencing reactions. The integrated devices allow the highly sensitive discrimination of optical signals using features such as spectra, amplitude, and time resolution, or combinations thereof. The arrays and methods of the invention make use of silicon chip fabrication and manufacturing techniques developed for the electronics industry and highly suited for miniaturization and high throughput.

Introduced here is an approach to mitigating (e.g., lessening or eliminating) the high-frequency interference pattern that is caused by uneven surfaces along the coupling interface formed between the waveguide and probe of an interferometric sensing system. The approach is to reduce the high-frequency interference pattern caused by the interference when a waveguidefor example, in the form of an optical fiberand a probe are directly coupled to one another. Specifically, the coupling surface of the waveguide can be treated, for example, with sandpaper, sandblasting, or acid etching, to create a frosted surface texture. In operation, the frosted surface scatters the light transmitted through the waveguide, preventing the high-frequency interference pattern from occurring.

A chip-scale, reusable sensor can detect aromatic hydrocarbons, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), rapidly in water without sample preparation. The device is capable of real-time, continuous monitoring for BTEX solutes, which diffuse into a film, such as a polymer, on the sensors surface. In operation, BTEX analytes concentrate in the film, causing an increase in refractive index, which modulates evanescent coupling into the chips integrated photodetector array. Integration of the photodetector array simplifies system instrumentation and permits incorporation of an on-chip photocurrent reference region in the immediate vicinity of the sensing region, reducing drift due to temperature fluctuations. In some examples, the chip responds linearly for BTEX concentrations between 1 ppm and 30 ppm, with a limit of detection of 359 ppb, 249 ppb, and 103 ppb for benzene, toluene, and xylene in water, respectively.

Arrays of integrated analytical devices and their methods for production are provided. The arrays are useful in the analysis of highly multiplexed optical reactions in large numbers at high densities, including biochemical reactions, such as nucleic acid sequencing reactions. The integrated devices allow the highly sensitive discrimination of optical signals using features such as spectra, amplitude, and time resolution, or combinations thereof. The arrays and methods of the invention make use of silicon chip fabrication and manufacturing techniques developed for the electronics industry and highly suited for miniaturization and high throughput.

A chip-scale, reusable sensor can detect aromatic hydrocarbons, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), rapidly in water without sample preparation. The device is capable of real-time, continuous monitoring for BTEX solutes, which diffuse into a film, such as a polymer, on the sensors surface. In operation, BTEX analytes concentrate in the film, causing an increase in refractive index, which modulates evanescent coupling into the chips integrated photodetector array. Integration of the photodetector array simplifies system instrumentation and permits incorporation of an on-chip photocurrent reference region in the immediate vicinity of the sensing region, reducing drift due to temperature fluctuations. In some examples, the chip responds linearly for BTEX concentrations between 1 ppm and 30 ppm, with a limit of detection of 359 ppb, 249 ppb, and 103 ppb for benzene, toluene, and xylene in water, respectively.

A chip-scale, reusable sensor can detect aromatic hydrocarbons, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), rapidly in water without sample preparation. The device is capable of real-time, continuous monitoring for BTEX solutes, which diffuse into a film, such as a polymer, on the sensors surface. In operation, BTEX analytes concentrate in the film, causing an increase in refractive index, which modulates evanescent coupling into the chips integrated photodetector array. Integration of the photodetector array simplifies system instrumentation and permits incorporation of an on-chip photocurrent reference region in the immediate vicinity of the sensing region, reducing drift due to temperature fluctuations. In some examples, the chip responds linearly for BTEX concentrations between 1 ppm and 30 ppm, with a limit of detection of 359 ppb, 249 ppb, and 103 ppb for benzene, toluene, and xylene in water, respectively.

A semiconductor structure includes a first optical waveguide and a second optical waveguide located on a sapphire substrate. The first optical waveguide and the second optical waveguide each include a core portion of gallium nitride (GaN), and a cladding layer laterally surrounding the core portion. The cladding layer includes a material having a refractive index less than a refractive index of the sapphire substrate.

A method of forming a semiconductor structure includes forming a first optical waveguide and a second optical waveguide on a sapphire substrate. The first optical waveguide and the second optical waveguide each include a core portion of gallium nitride (GaN), and a cladding layer laterally surrounding the core portion. The cladding layer includes a material having a refractive index less than a refractive index of the sapphire substrate. The method further includes etching a portion of the cladding layer to form a microfluidic channel therein and forming a capping layer on a top surface of the first optical waveguide, the second optical waveguide and the microfluidic channel.

A method of forming a semiconductor structure includes forming a first optical waveguide and a second optical waveguide on a sapphire substrate. The first optical waveguide and the second optical waveguide each include a core portion of gallium nitride (GaN), and a cladding layer laterally surrounding the core portion. The cladding layer includes a material having a refractive index less than a refractive index of the sapphire substrate. The method further includes etching a portion of the cladding layer to form a microfluidic channel therein and forming a capping layer on a top surface of the first optical waveguide, the second optical waveguide and the microfluidic channel.

In one embodiment, a microfluidic platform for optical biosensing, the platform including an optical substrate, a layer provided on the substrate, and a channel formed within the layer through which fluid can flow, the channel including a constriction that is adapted to trap a microsphere suspended in the fluid when the fluid flows through the channel.