A colorimetric sensor for detecting an analyte of interest in a fluid sample includes a lamellar photonic material having alternating layers of a first polymer layer and a second polymer layer. Each first polymer layer can be a molecularly imprinted polymer defining a cavity shaped to receive an analyte of interest. The photonic material is configured such that, when an analyte contacts the photonic material and becomes disposed within a cavity of the molecularly imprinted polymer, a refractive property of the photonic material changes, causing a detectable color change in the sensor.

Techniques are disclosed for a chemical sensor architecture based on a fabric-based spectrometer. An example apparatus implementing the techniques includes a portable spectrometer device including a first fabric layer and a second fabric layer coupled to the first fabric layer to form a pouch. The second fabric layer includes a fiber fabric spectrometer substrate comprising a fiber material including one or more electronic devices, wherein the pouch is configured to receive a colorimetric substrate and the fiber fabric spectrometer substrate is configured to measure reflectance of a colorimetric substrate disposed in the pouch.

A colorimetric sensor array includes a CMOS image sensor having a surface including pixels and a multiplicity of colorimetric sensing elements. Each sensing element has a sensing material disposed directly on one or more of the pixels. The colorimetric sensing elements are distributed randomly on the surface of the CMOS image sensor. Fabricating the colorimetric sensor array includes spraying a sensing fluid in the form of droplets directly on a surface of a CMOS image sensor and removing the solvent from the droplets to yield a multiplicity of sensing elements on the surface of the CMOS image sensor. Each droplet covers one or more pixels of the CMOS image sensor with the sensing fluid. The sensing fluid includes a solvent and a sensing material. The droplets are distributed randomly on the surface of the CMOS image sensor.

Methods for making nanocomposites are provided. In an embodiment, such a method comprises combining a first type of nanostructure with a bulk material in water or an aqueous solution, the first type of nanostructure functionalized with a functional group capable of undergoing van der Waals interactions with the bulk material, whereby the first type of nanostructure induces exfoliation of the bulk material to provide a second, different type of nanostructure while inducing association between the first and second types of nanostructures to form the nanocomposite.

A detection device (10), comprising a sample detection layer (1) provided thereon with a detection reagent reacted with an analyte and a result display region (18), wherein the device further comprises a symbol display layer (2) on which an indicator (21) is processed; after the indicator contacts with a gas which can change the color of the indicator, the indicator changes from a first color to a second color.

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 devices allow the highly sensitive discrimination of optical signals using features such as spectra, amplitude, and time resolution, or combinations thereof. The devices include an integrated diffractive beam shaping element that provides for the spatial separation of light emitted from the optical reactions.

In an embodiment, a method for fabrication of VOC sensor comprises dissolving one or more metal precursors in a reagent to form a solution, adding a reducing agent to precipitate a metal oxide compound, subjecting the solution to acoustic energy, recovering a nanoscale metal oxide, and forming a sensing layer in a chemo-resistance sensor using the nanoscale metal oxide.

Disclosed are systems and methods for the robust passive detection of airborne toxins using a colorimetric sensor coating onto a optically transparent substrate. In certain embodiments, the substrate is affixed to an adhesive material (tape). In certain embodiments, the sensor and substrate are transparent. In various embodiments, multiple sensors are coated onto selected substrate for the simultaneous detection of multiple toxins. In various embodiments, the sensed or detected toxins include a number of chemical warfare agents and toxic industrial chemicals. In various implementations, the tape is affixed to a remote surface, which may be visually monitored by a camera directly by focusing the camera on the tape or may be affixed to a camera lens by an adhesive backing, such that colorimetric sensor changes may be observed through the lens itself. Sensor claddings consist of optical grade polymers immobilized with colorimetric and/or fluorescent indicators that undergo optical changes upon exposure to their target analyte. Typical substrate cross-linked polymers are urethane acrylate polymer based, co-polymerized with silicone backbone such as dimethyl siloxane, which in general is chemically inert, yet leaves the polymer with the large free-volume necessary for rapid target diffusion. The polymer is cured after immobilization with target indicator mixture, and simultaneously cross-linked by UV light or heat.

A method for the production of a sol-gel based matrix resulting in a sol-gel based matrix with high stability and high porosity. The sol-gel based material may be used for the production of a composite or sensor suitable for monitoring analytes.

The present invention provides a method for increasing the sensitivity of LFIAs by using palladium nanoparticles, selecting appropriate dye chemistries, and improving the timing of the development chemistry. In the presence of a palladium nanoparticle, three reagents interact with a catalytic label to form a colored dye. The three reagents include a hydrogen peroxide source, a color developer (a substituted para-phenylenediamine), and a color coupler (e.g. a napthol or a phenol). The timing of the development chemistry is improved by any combination of using a reducing agent, delaying hydrogen peroxide application by diffusion, using dissolving materials as a time delay, using serpentine flow, and separating the color coupler and the color developer on the strip.