Abstract: Integrated microfluidic ejector chips and methods of use are provided. An example of an integrated microfluidic ejector chip includes a first set of microfluidic ejectors fed with a reference solution, and a second set of microfluidic ejectors fed with a sample solution. The first set of microfluidic ejectors and the second set of microfluidic ejectors are disposed on the integrated microfluidic ejector chip to print a pattern of proximately located spots on a sensor.

Abstract: A luminescence-enhancement system can include a luminescence-enhancement sensor having a substrate and a group of nanofingers with individual nanofingers that can be flexible and include a support end attached to the substrate, a distal tip positioned distally with respect to the substrate, and a middle portion between the support end and the distal tip. A coating of a metal or metal alloy can be applied to the substrate and the distal tip that is conductively continuous. The middle portion can be devoid of the coating or the coating at the middle portion is conductively discontinuous. A liquid ejector can be present and can include a jetting nozzle to eject a liquid droplet having a volume of 2 pL to 10 ?L. The group of nanofingers and the jetting nozzle can be positionable relative to one another for the droplet to be deposited on the group of nanofingers.

Abstract: A system and a method for on-chip dilution of a calibration solution are provided. An exemplary system includes a microfluidic ejector chip. The microfluidic ejector chip includes a calibration reservoir to contain a calibration standard and a dilution reservoir to contain a dilution solvent. A first fluid control device couples the calibration reservoir to a mixing chamber, and a second fluid control device couples a dilution reservoir to the mixing chamber. The mixing chamber is fluidically coupled to a microfluidic ejector.

Abstract: Systems and methods for generating calibration curve for a sensor are provided. An example method includes printing at least two spots of an analyte on the sensor, wherein each of the spots includes a different number of overprinted droplets ejected from a single printhead.

Abstract: In an example method, an ordered array of microdots including an analyte printed on a surface of a surface-enhanced substrate of an analysis chip is probed with an excitation beam of electromagnetic radiation. Emitted radiation is detected from a number of microdots of the ordered array of microdots. Calibration data is generated for the analysis chip with respect to the analyte based on a detected shift in the emitted radiation as compared to the excitation beam.

Abstract: A microporous structure includes an array of nano wires and a coating about the nano wires of the array. The coating defines pores between the nano wires.

Abstract: A spectroscopic device is provided. The spectroscopic device includes a plurality of design groups on a substrate. Each design group includes a plurality of collapsed groups separated by bare regions of substrate, wherein the edges of each design group is configured to enhance the pinning of a solvent drying line at the edge of the design group. Each collapsed group comprises at least 2 flexible columnar structures, and each flexible columnar structure comprises a metal cap.

Abstract: In one example, an apparatus includes a surface-enhanced substrate having a microdot deposited onto a surface thereon via a microfluidic ejector. The microdot includes a predetermined concentration of an analyte.

Abstract: An example of an apparatus includes a plurality of wells, wherein each well is to receive a cell culture and a cell culture liquid. The apparatus also includes a collector to contact the cell culture liquid in a well selected from the plurality of wells. The collector is to draw a microfluidic sample of the cell culture liquid from the well. In addition, the apparatus includes a sensor substrate to receive the microfluidic sample, wherein the sensor substrate is to be used to measure a characteristic of the cell culture liquid. Also, the apparatus includes a microfluidic channel to transport the microfluidic sample from the collector to the sensor substrate.

Abstract: An example of an apparatus includes an inlet to receive a plurality of cells suspended in a solution. The apparatus also includes a microfluidic channel to transport the plurality of cells suspended in the solution. In addition, the apparatus includes a trap disposed along the microfluidic channel, wherein the trap is to isolate the plurality of cells suspended in the solution. Also, the apparatus includes a buffer supply to dispense a buffer to wash the plurality of cells and to remove the solution from the microfluidic channel. The apparatus further includes a sensor to measure a characteristic of the plurality of cells after isolated from the solution.

Abstract: A surface enhanced luminescence analyte nano pillar stage may include a substrate, an array of closable pillars extending from the substrate and a fluid supply connected to the array of pillars. The fluid supply is to at least partially replenish fluid amongst the pillars of the array that has evaporated to maintain a level of the fluid amongst the pillars of the array below tops of the pillars.

Abstract: A luminescence-enhancement system can include a luminescence-enhancement sensor having a substrate and a group of nanofingers with individual nanofingers that can be flexible and include a support end attached to the substrate, a distal tip positioned distally with respect to the substrate, and a middle portion between the support end and the distal tip. A coating of a metal or metal alloy can be applied to the substrate and the distal tip that is conductively continuous. The middle portion can be devoid of the coating or the coating at the middle portion is conductively discontinuous. A liquid ejector can be present and can include a jetting nozzle to eject a liquid droplet having a volume of 2 pL to 10 ?L. The group of nanofingers and the jetting nozzle can be positionable relative to one another for the droplet to be deposited on the group of nanofingers.

Abstract: A spectroscopic device is provided. The spectroscopic device includes a plurality of design groups on a substrate. Each design group includes a plurality of collapsed groups separated by bare regions of substrate, wherein the edges of each design group is configured to enhance the pinning of a solvent drying line at the edge of the design group. Each collapsed group comprises at least 2 flexible columnar structures, and each flexible columnar structure comprises a metal cap.

Abstract: A surface enhanced luminescence (SEL) sensing stage may include a matrix and plasmonically active nanostructures retained within the matrix, wherein no greater than 10% of the plasmonically active nanostructures consist of a single unagglomerated plasmonically active nano particle.

Abstract: The present disclosure is drawn to a photoacoustic explosives detector, including a sample chamber, an aerosolizing ejector, a light source, and a pressure differential sensor. The sample chamber can include a photoreaction region, and the aerosolizing ejector can be positioned to eject 3 pL to 10 nL droplets of a liquid sample into the photoreaction region. A light source can be directed to emit focused light through the photoreaction region, and a pressure differential sensor can be positioned with respect to the photoreaction region to sense degradation of the droplets exposed to the focused light.

Abstract: A microfluidic chip may include a substrate, chamber supported by the substrate, a sacrificial material in the chamber, a spectroscopically active nano particle assembly anchored within the chamber by the sacrificial material and a fluid supply port connected to the chamber. Each spectroscopically active nano particle assembly may include a cluster of nanoparticles.

Abstract: A surface enhanced luminescence analyte nano pillar stage may include a substrate, an array of closable pillars extending from the substrate and a fluid supply connected to the array of pillars. The fluid supply is to at least partially replenish fluid amongst the pillars of the array that has evaporated to maintain a level of the fluid amongst the pillars of the array below tops of the pillars.

Abstract: In an example implementation, a substance detection method includes sensing for fluid in a chamber of a substance detection device. When fluid is sensed in the chamber, the method includes sensing again for fluid in the chamber. When no fluid is sensed in the chamber, the method includes initiating a substance detection process.

Abstract: Provided in one example is an analyte detection package that includes a chamber, a surface-enhanced luminescence analyte stage within the chamber, and a lens integrated as part of the package to focus radiation onto the analyte stage.

Abstract: A spectroscopically active nano-particle assembly is provided. The nano-particle assembly includes a cluster of metallic nano-particles. A first protective coating is formed over a first side of the cluster, and a second protective coating is formed over a second side of the cluster, wherein the second side of the cluster is opposite the first side.