A system for detecting COVID-19 infection, including a colorimetric sensor, an image-capturing device, and a processing unit. The colorimetric sensor includes an array of chemical receptors configured to be exposed to exhaled breath of a person suspected to be infected by COVID-19 virus. The array of chemical receptors includes an array of metalloporphyrazines, an array of organic dyes, an array of metalloporphyrins, an array of metal ion complexes, and an array of functionalized gold nanoparticles (AuNPs). The processing unit is configured to perform a method utilizing the image-capturing device. The method includes capturing a first image from the array of chemical receptors before exposure to exhaled breath, capturing a second image from the array of chemical receptors after exposure to exhaled breath, and detecting COVID-19 infection status of the person by analyzing color changes of the array of chemical receptors in the second image respective to the first image.

Sensors arrays that include indicators arranged in a pattern on a substrate. The indicators include nucleophilic indicators. In some examples, the sensor arrays with multiple nucleophilic indicators provide superior detection and identification of microorganisms, cancer biomarkers, formaldehyde, organophosphates, and aldehydes.

The problem of detecting whether a urine sample is true human urine or a counterfeit urine product is solved by the use of reagent systems that detect two markers normally present in human urine. The markers acid phosphatase and alkaline phosphatase catalyze the substrates thymolphthalein monophosphate and p-nitrophenol phosphate, respectively. These substrates are formulated as spot tests on a dip stick or as reagents for use in automated chemical analyzers. The presence of the markers can be qualitatively detected by color-changes in the sample, formed by the pH-specific chromogens that result from catalysis of the substrates with the markers. The control reagent can further indicate whether a counterfeit urine product contains one or both of the chromogens.

A screening test paper reading system includes a reading and light illumination unit which has a reading device and a light illumination device, a screening test paper having a reaction zone arranged thereon for reacting chemically with a number of specific specimens and change its color accordingly, an optical analyzing unit connected to the reading and light illumination unit, and analyzing spectrum signals of a screened line image received from a reaction zone on a screening test paper. Notably, the reading device reads spectrum signals of an reflected image from the screened line after illuminated in the reaction zone and then transmits the spectrum signals of the reflected image subsequently to the optical analyzing unit for computing and analyzing.

A micro-colorimetric sensor for sensing target chemicals using edge tracking includes a substrate. A plurality of parallel linear channels of porous media is entrenched into the substrate and each linear channel includes a sensing material adapted to sense one of several specific target chemicals in air. The plurality of parallel linear channels is separated by barrier material from the adjacent parallel linear channel where the barrier material blocks diffusion of chemicals from one linear channel to another. A plate is affixed over the substrate top to cover the plurality of parallel linear channels. An air sample is diffused along the micro-colorimetric sensor and color images are captured. An intensity profile is derived from the plurality of color images to determine a maximum and a minimum intensity value along the sensor. A plurality of positions along the sensor is tracked to determine an edge position.

The present disclosure relates to using color calibration to improve and increase the accuracy of interpreting color-sensitive results from test strips made of substrates like paper. This is accomplished via a diagnostic test unit including a substrate, at least one region on the substrate, a reagent placed within the region to react, and a series of color legends on the substrate. Different reagent samples may be placed on the separate regions of a substrate for testing. An imaging device is used to capture the reaction results. More precise readings can be obtained by comparing the reaction results to the color legends to determine the measured property of the analyte.

The invention relates to a detection system for an electronic nose capable of detecting and identifying a set of compounds that can be found in a gaseous sample, the detection system comprises a plurality of cross-reactivity detection sensors (D1, D2, D3, D4, D5, D6, D7) for supplying signals representing the presence of one or more compounds of said set in the gaseous sample, and which is particularly characterised in that the detection system further comprises at least one reference sensor (RI) for supplying a signal representing the measurement noise of the detection system. The detection system further relates to an electronic nose comprising such a detection system.

A micro-colorimetric sensor for sensing target chemicals that converts time sequence information into a spatial distribution of color. By tracking the spatial color distribution, chemical exposure over time is thus detected, which overcomes the limitation of traditional colorimetric sensors. A porous media is coated on a top surface of the substrate. Multiple sensing chemicals are fused in parallel linear channels into the porous media coating. A plate is affixed over the substrate top surface to cover the plurality of parallel linear channels. An air sample is diffused along the porous media to get a clear pattern of spatial color distribution and color images are captured. Optical parameters like gradient of spatial color distribution, intensity, and absorbance, etc., can be tracked to calculate analytes concentrations.

The present disclosure relates to probes for analyzing a chemical composition, and related methods of analyzing a chemical composition and of manufacturing probes for analyzing a chemical composition. A benefit of the disclosed probes and methods can include luminescent chemical sensor arrays for rapid, accurate, portable and economical qualitative and quantitative analysis of a broad range of chemical compositions. A benefit of the methods disclosed herein can include the rapid, simple, and accurate analysis of trace chemicals present in chemical compositions.

A system and method for forming a low cost optical sensor array. The sensor includes an optical fiber; a first nanocomposite thin film along at least a portion of the optical fiber for interrogating a first parameter through a correlated signal having a first wavelength; and a second nanocomposite thin film along at least a portion of the optical fiber for interrogating a second parameter through a correlated signal having a second wavelength different from the wavelength of the first parameter.