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 test device is configured for diagnostic testing and includes an optical readable medium, in turn including a pattern of spots of material arranged on a surface of the device. Several patterns may be provided. The patterns accordingly formed may be human and/or machine readable. They may notably encode security information, e.g., indicating whether the device has already been used. The spots may notably be inkjet spotted. In addition, a method is provided for decoding information encoded in a pattern of such a test device. In embodiments, liquid is introduced in the device, which comprises additional spots having a substantially different solubility than spots forming the actual pattern. Thus, the additional spots get solubilized in and flushed by the liquid as the latter wets them, and an initially hidden pattern may be read, which is formed of the remaining spots (not solubilized). Encoding methods are also provided.

A sensing system for characterizing analytes of interest in a sample comprises a photonic integrated circuit with an integrated interferometer. The integrated interferometer is configured for spectroscopic operation. The integrated interferometer comprises at least a sensing arm and a reference arm, both the sensing arm and the reference arm having an exposable segment available for interaction with the sample, whereby the exposable segment of the reference arm has an optical path length which is smaller than twice the optical path length of the exposable segment of the sensing arm. The exposable section of the sensing arm is selective to the analyte of interest, whereas the exposable section of the reference arm is not selective to the analyte of interest.

Systems and methods are provided for identification of a detection event relevant in applications focused on real-time or near real-time reporting in a continuous monitoring application. A controller collects data from a plurality of sensors and compares recent data to background data to determine whether an event has occurred. A system in accordance with an embodiment of the present disclosure is considered to have detected an event of interest when at least a specified minimum number of sensors report a detection event at the same time.

A method of quantifying the amount of glucose in a sample is provided herein that may further comprise an interferent such as mannitol. At least two measurements are obtained using measurement methods that differ in their sensitivity to the amount of interferent in the sample, thus enabling the results to be compared to determine whether any interferent is present in the sample. A glucose sensor for carrying out a method described herein is also provided.

An optochemical sensor comprises a measuring element excitable by the light of an excitation light source and in contact with a medium to be measured, and a measuring arrangement including at least one excitation light source and a detector as well as a hood separating the measuring arrangement from the measuring element, wherein the excitation light source and the detector are fixed to a base plate arranged in parallel with the measuring element, the hood, the excitation light source and the detector are separated from one another by at least a portion of the material thickness of the hood, and light from the excitation light source through an optical waveguide impinges on the measuring element at such an angle that fluorescence light emitted by the measuring element impinges perpendicularly on the detector.

The present disclosure provides methods and systems for performing single-molecule detection using fabricated integrated on-chip devices. In an aspect, the present disclosure provides a method for on-chip detection of an array of biological, chemical, or physical entities, comprising: (a) providing an array of light sensing devices; (b) immobilizing the array of biological, chemical, or physical entities on a substrate of the array of light sensing devices; (c) exposing the array of biological, chemical, or physical entities to electromagnetic radiation sufficient to excite the array of biological, chemical, or physical entities, thereby producing an emission signal of the array of biological, chemical, or physical entities; (d) using the array of light sensing devices, acquiring pixel information of the emission signal of the array of biological, chemical, or physical entities without scanning the array of light sensing devices across the array of biological, chemical, or physical entities; and (d) detecting the array of biological, chemical, or physical entities based at least in part on the acquired pixel information.

The discrimination ability of a chemical sensing cross-reactive arrays is enhanced by constructing sensing elements in two dimensions, first in the x-y plane of the substrate, second in the z dimension so that the sensors are vertically stacked on top of one another. Stacking sensing elements on top of one another adds to the discrimination ability by enabling the characteristic measurement of how fast target chemicals are passing through the stack of sensors. The new invention also allows the ability to discriminate components in a sample mixture by separating them using their innate difference in diffusional rates. Multi-sensor response patterns at each z level of sensors and time delay information from the sample passing from one level to the next are used to generate the response vector. The response vector is used to identify individual component samples and components in a mixture sample.

Method and compositions using transition metal salts and/or ammonium chloride to liberate toxins and other molecules from cyanobacteria, useful for assaying for total cyanobacterial toxins in lakes, reservoirs and other waters.

Provided herein are systems and methods of assessing a concentration of iron in a body fluid sample, such as whole blood. Systems include a highly stable, fast reacting, and accurate sensing area of a sensor for contacting with a body fluid sample, wherein upon contact, the body fluid sample causes a color change to the sensor that correlates with the concentration of iron in the body fluid sample. The disclosed systems and methods generate one or more signal outputs of light intensity data, from which the concentration of iron in the body fluid sample is determined.