An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.

Provided by the inventive concept or nanoplastic or microplastic particles, reference standard materials including nanoplastic or microplastic particles, methods of using, and methods of preparing the same. Uses of the nanoplastic and/or microplastic particles of the inventive concept include tracking of nanoplastic and/or microplastic particle dispersion/distribution in environmental and/or biological systems, as well as in organisms that are within the environment.

Fluorescent pigment is introduced into the plastic composition, preferably a thermoplastic, especially polyethylene or polypropylene, in the granules formation stage, in addition to possible standard components of the composite, mixed, granules are formed, and then the granules are formed into a finished building material component, and then, with the help of a known fluorimeter, the fluorescence intensity of individual parts of the surface of a plastic element is measured and the homogeneity of the material is inferred on the basis of the differences in the results of the fluorescence intensity measurements.

A time-resolved fluorescence immunochromatographic test paper card for testing clothianidin. A binding pad includes a detection microsphere and a quality control microsphere thereon, wherein the detection microsphere is a fluorescent microsphere coated with a clothianidin monoclonal antibody on the surface thereof, the quality control microsphere is a fluorescent microsphere coated with a rabbit anti-tag protein on the surface thereof. An NC film is provided with a detection line and a control line. The lengths of the detection line and the control line are the same as the width of the NC film. A first clamping part is arranged at one end of the sample pad. A second clamping part and a third clamping part are respectively arranged at two ends of the binding pad. A fourth clamping part is arranged at one end of the NC film, the other end of the NC film is joined with an absorption pad.

An optochemical sensor unit including: an optical waveguide; a transmitting unit for emitting a first transmission signal for exciting a luminophore; a receiving unit for receiving a received signal comprising a signal component emitted by the excited luminophore; a measuring chamber for receiving a fluid, wherein the fluid includes magnetic microspheres; a membrane arranged between the measuring chamber and a measuring medium for exchanging an analyte between the measuring medium and the fluid in the measuring chamber, wherein the measuring diaphragm is impermeable to the magnetic microspheres; and an electromagnet for attracting magnetic microspheres to a sensor membrane with a fluid-contacting surface and/or to a fluid-contacting surface of the optical waveguide, or to a surface of a transparent substrate layer of the optical sensor unit that is connected to the optical waveguide.

The present disclosure relates to compounds of Formula I, II, or III and compositions of the same, which are reversible off-on or ratiometric fluorescent iron sensors and are useful in live-cell imaging of labile iron ions and their quantification in subcellular compartments, as well as treatment of diseases associated with iron dyshomoestasis.

The invention relates to a multi-layered packaging foil comprising a layer L-1 having an oxygen gas transmission rate OGTR-1; a luminescent compound having the property that its luminescence is capable of being quenched by oxygen; and a layer L-2 adhering to L-1 and to the luminescent compound. The layer L-2 has an oxygen gas transmission rate OGTR-2 that is at least 20 times higher than OGTR-1, and the luminescent compound is present between L-1 and L-2. The invention further relates to a packaging comprising a packaging foil of the invention and to a method for measuring the oxygen content in a packaging.

Disclosed in the disclosure is a method for detecting acetaldehyde in wine samples using fluorescent probes, belonging to the field of wine quality control. The detection method of the disclosure is used for measuring acetaldehyde in wines based on fluorescent probes. Under the acidic condition of pH=2.0, the specific binding between the fluorescent probe and acetaldehyde is realized according to the principle of photoelectron induced transfer. The fluorescent probe has a good linear relationship with the concentration of acetaldehyde in a range of 0-200 mg/L, the limit of detection (LOD) is 3.6×10.sup.−8 mol/L, and the recovery rate of samples is 94.02-108.12%. The detection method has the advantages including low cost, wide linear range, high sensitivity, and being fast and accurate. The fluorescent probe is successfully applied to the detection and analysis of wine samples and samples in a beer fermentation process.

Provided are a moisture detection sensor, a defect detection sensor, and a sensor array using the same that make use of moisture-sensitive compounds reversibly reacting to water (moisture) to emit fluorescence, thereby reversibly sensing the moisture within a short period of time and also providing a high degree of sensitivity even to an extremely small quantity of moisture. The moisture detection sensor includes one or more moisture-sensitive compounds selected from the group consisting of Calcein, Calcein-AM (Calcein acetoxymethyl ester), and Calcein blue.

Disclosed herein are graphene quantum dot tagged paraffin suppressants such as graphene tagged paraffin inhibitors and paraffin dispersants and methods of making and using thereof. The graphene quantum dots are covalently bound to residues of paraffin inhibitors or dispersed with paraffin dispersants to form tagged paraffin suppressants active in inhibiting paraffin crystallization or dispersing crystalized paraffin wax in crude oils and compositions comprising crude oils. The dots can be tailored to fluoresce at wavelengths with minimized correspondence to the natural fluorescence of crude oils, enabling the measurement of the concentration of the paraffin suppressants in crude oils or compositions comprising crude oils. The tagged suppressants are used to trace the dispersion and disposition of the paraffin suppressants in oils and compositions comprising them, for example within crude-oil recovery, production, processing, or conveyance and transportation, by in situ sampling the oil or composition and measuring the fluorescence of the sampled material.