Abstract: An explosive detection system for detecting explosive trace in a sample includes a detection unit, and a processing unit. The detection unit that receives a desorbed sample includes a first heater, a second heater, a first resistance temperature detector (RTD), a second RTD, and an amplifier. The first heater is exposed to the desorbed sample. The first heater and the second heater are supplied with specific voltage for three or more experiments. The first RTD and the second RTD measure changes in resistance due to heating of the first heater and the second heater to calculate voltages across the first RTD and the second RTD. The amplifier amplifies the voltages to calculate a differential voltage for each of the three or more experiments, and converts the differential voltage into a digital signal. The processing unit is configured to process the digital signal to detect explosive trace in the desorbed sample.

Abstract: An explosive detection system for detecting explosive trace in a sample includes a detection unit, and a processing unit. The detection unit that receives a desorbed sample includes a first heater, a second heater, a first resistance temperature detector (RTD), a second RTD, and an amplifier. The first heater is exposed to the desorbed sample. The first heater and the second heater are supplied with specific voltage for three or more experiments. The first RTD and the second RTD measure changes in resistance due to heating of the first heater and the second heater to calculate voltages across the first RTD and the second RTD. The amplifier amplifies the voltages to calculate a differential voltage for each of the three or more experiments, and converts the differential voltage into a digital signal. The processing unit is configured to process the digital signal to detect explosive trace in the desorbed sample.

Abstract: A seamless microchannel with aligned microelectrodes structure can be prepared to include a polymeric body defining a surface of a seamless microchannel. The microchannel is seamless in that it is formed by a single body of material having a conduit that is open at one surface and extends to another opening aligned with microelectrodes in another surface of the body. The rest of the microchannel is closed and defined by the single body of material. The seamless microchannel structure can be used in methods that include biosensors, coupling waveguides, capillary electrophoresis chips, microreactors, polymerase chain reaction-chips, and solving mathematical problems.

Abstract: A biosensor having an optical fiber having at least one curved portion configured to enhance penetration of evanescent waves; and one or more nanoparticles associated with the optical fiber, and configured to enhance localized surface plasmon resonance.

Abstract: A biosensor having an optical fiber having at least one curved portion configured to enhance penetration of evanescent waves; and one or more nanoparticles associated with the optical fiber, and configured to enhance localized surface plasmon resonance.

Abstract: A biosensor having an optical fiber having at least one curved portion configured to enhance penetration of evanescent waves; and one or more nanoparticles associated with the optical fiber, and configured to enhance localized surface plasmon resonance.

Abstract: A microfabricated analysis chip with integrated waveguides for evanescent field absorption detection is provided. Fabrication of the microfluidic device may be performed by micropatterning a layer of photoresist or other suitable material using a single step photoresist process to produce a microchannel and an optical structure (e.g., a U-bend waveguide) in the microfluidic device. The microfluidic device couples a micro-channel network with a waveguide in a collinear fashion to maintain higher path length and incurring little or no scattering, dispersion, and divergence losses. A sample can be passed through the microchannel while light is transmitted through the waveguide. Any change in refractive index as well as change in optical absorbance property of fluid flowing in the microchannel can be detected by detecting changes in light output power (e.g., changes in absorbance). A change in concentration of solution in the microchannel can be determined by detecting a change in light absorbance output.

Abstract: A seamless microchannel with aligned microelectrodes structure can be prepared to include a polymeric body defining a surface of a seamless microchannel. The microchannel is seamless in that it is formed by a single body of material having a conduit that is open at one surface and extends to another opening aligned with microelectrodes in another surface of the body. The rest of the microchannel is closed and defined by the single body of material. The seamless microchannel structure can be used in methods that include biosensors, coupling waveguides, capillary electrophoresis chips, microreactors, polymerase chain reaction-chips, and solving mathematical problems.

Abstract: A microfabricated analysis chip with integrated waveguides for evanescent field absorption detection is provided. Fabrication of the microfluidic device may be performed by micropatterning a layer of photoresist or other suitable material using a single step photoresist process to produce a microchannel and an optical structure (e.g., a U-bend waveguide) in the microfluidic device. The microfluidic device couples a micro-channel network with a waveguide in a collinear fashion to maintain higher path length and incurring little or no scattering, dispersion, and divergence losses. A sample can be passed through the microchannel while light is transmitted through the waveguide. Any change in refractive index as well as change in optical absorbance property of fluid flowing in the microchannel can be detected by detecting changes in light output power (e.g., changes in absorbance). A change in concentration of solution in the microchannel can be determined by detecting a change in light absorbance output.

Abstract: A biosensor having an optical fiber having at least one curved portion configured to enhance penetration of evanescent waves; and one or more nanoparticles associated with the optical fiber, and configured to enhance localized surface plasmon resonance.