A chemical indicator strip for detecting disinfectant that includes a film substrate, and an indicator portion with a first and a second ink. The first and the second ink can react in the presence of a threshold level of disinfectant for a threshold level of exposure time. The chemical indicator strip can be used in a method of detecting a threshold level of disinfectant. The method can include exposing a chemical indicator strip to a concentration of disinfectant for a preset amount of time. The method can include providing a visual indicator to a user that changes from a first color to a second color. The method can indicate that the chemical indicator strip has been exposed to a threshold concentration of disinfectant for a threshold amount of time when a complete color change occurs on the chemical indicator strip from the first color to the second color.

A biomarker detection apparatus in which a CMOS-based chip is used to generate independent detection signals from a reaction zone that receives a biological sample, where the biological sample is provided to both a test region and positive and negative control regions within the reaction zone. The independent detection signals can be processed together (i.e. as a group of input parameters for an algorithm) to identify the presence of a biomarker (or a plurality of biomarkers) in a biological sample. The use of sample-specific, independently detectable positive and negative controls facilitates improved detection accuracy.

An exemplary embodiment of the present disclosure provides a biosensor that can facilitate detection of the molecules creatinine, creatine and/or sarcosine in a minimal-equipment, portable, and low-cost fashion. Some aspects of the disclosure relate to methods and systems to enable quantitative measurement of certain biomarkers at the point of care without expensive instrumentation.

An apparatus and method for measuring hydrogen peroxide concentration in water to an accuracy of 0.1 ppm comprises a colorimetric assay method to determine hydrogen peroxide concentration. The assay is monitored spectophotometrically at a desired wavelength. Each sample is corrected relative to a control sample and hydrogen peroxide concentration determined with respect to a standard curve.

A composition, method and kit for quantifying the concentration of one peracid or the total concentration of two or more peracids in a water source are disclosed. In particular, an oxidation sensitive or peroxycarboxylic acid selective leuco dye is used to react only with one or more peroxycarboxylic acids in a water source but not with peroxide usually co-existing in the water source. Not only does the oxidation sensitive or peroxycarboxylic acid selective leuco dye react with peracid(s) but also the reaction generates a color species that can be used visually or through absorbance measurement to quantify the peracid concentration. The method disclosed here is not a titration method, it involves a simple mixing step. The kit or composition disclosed here does not utilize a catalyst, such as iodine.

The invention provides an analytical process, which preferably is a one-step process, for detecting in a sample peroxide-based explosives, nitrate-based explosives and/or nitramine-based explosives, the process comprising contacting a sample suspected of containing a peroxide-based compound, especially a peroxide-based explosive, a nitramine, nitrate ester or a nitrate salt, especially a nitrate-based explosive and/or a nitramine-based explosive, with a composition comprising a Ni-porphyrin, an acid and preferably an acid-stable solvent.

A chemical indicator device for use in detecting exposure to an oxidizing agent, such as hydrogen peroxide, comprising a substrate or support upon which is disposed a chemical indicator composition (ink) for detecting an oxidizing agent, such as hydrogen peroxide. The chemical indicator composition further comprises an indicator dye that achieves a distinct range of different color changes with clear transitions between colors, upon exposure to different doses of the oxidizing agent, thus allowing for both a qualitative and semi-quantitative assessment of exposure to the agent.

An optical sensing element for use in the detection of hydrogen peroxide includes a sensing compound provided as a coating on a substrate. The sensing compound, on exposure to hydrogen peroxide, forms a luminescent reporter compound when excited with stimulating radiation at a predetermined wavelength that the sensing compound does not absorb.

The disclosed hydrogen peroxide indicator includes a substrate on which is disposed an indicator composition that includes at least one of a select group of indicator compounds and a catalyst. As a result of contact with hydrogen peroxide, the indicator composition changes color, even from colorless to having a visually observable color, thereby providing an indication of the presence of hydrogen peroxide.

The invention provides a percarboxylic acid concentration-determining device capable of determining the concentration of percarboxylic acid contained in an aqueous solution for chemical sterilization or disinfection that contains a percarboxylic acid as an active ingredient; and an indicator solution for use in preparing the device. The indicator solution contains a starch, an iodide, a thiosulfate, a water-soluble organic solvent, and water, with the starch, the iodide, the thiosulfate, and the water-soluble organic solvent being present in the following proportions, based on the total amount taken as 100 mass %: (a) starch: 0.01 to 5 mass %; (b) iodide: 0.01 to 5 mass %; (c) thiosulfate: 0.01 to 10 mass %; and (d) water-soluble organic solvent: 0.1 to 40 mass %, wherein the total amount of (a), (b), and (c) is greater than 0.6 mass %.