Abstract: A method of determining a disinfectant composition of a municipal water supply from a water sample that includes: (a) obtaining a water sample from a water source at a sampling location; (b) adding a chlorine-containing material to the water sample in the presence of an oxidation reduction potential (ORP) measurement device; (c) generating a plurality of ORP measurements during addition of the chlorine-containing material to the water sample; (d) estimating a concentration of one or more of free ammonia, fully combined ammonia, monochloramine, or a mixture of dichloramine and trichloramine in the water sample in which the estimation is derived from the relationship between the added chlorine material and the plurality of ORP measurements; and (e) determining a disinfectant composition of the water source at the water sampling location from the concentration calculation. A method of determining free ammonia composition is also included.

Abstract: The invention relates to a colorimetric gas detector for determining and monitoring gaseous substances. The colorimetric gas detector can be used in any application requiring the detection of substances in a gaseous environment. The colorimetric gas detector has a photodetector, a light source positioned opposite to the photodetector, and a receiving slot for positioning a colorimetric media between the camera and the light source.

Abstract: Tracing subterranean fluid flow includes providing a first polymeric tracer to a first injector, collecting a first aqueous sample from a first producer, and assessing the presence of the first polymeric tracer in the first aqueous sample. The first polymeric tracer includes a first polymer formed from at least a first monomer. The presence of the first polymeric tracer in the first aqueous sample is assessed by removing water from the first aqueous sample to yield a first dehydrated sample. pyrolyzing the first dehydrated sample to yield a first gaseous sample, and assessing the presence of a pyrolization product of the first polymer in the first gaseous sample. The presence of the pyrolization product of the first polymer in the first gaseous sample is indicative of the presence of a first subterranean flow pathway between the first injector location and the first producer location.

Abstract: A system is provided for identifying the presence of a target molecule or ion. The system comprises a solid support, and at least one chemical reagent applied to the solid support. Each chemical reagent produces a presumptive color indication that identifies or excludes the presence of a target molecule or ion.

Abstract: A method for calculating an amount of ammonia present in a gas sample is provided. The method includes receiving a first gas sample by a hydrogen analyzer. The first gas sample contains ammonia. The method also includes receiving a second gas sample by the hydrogen analyzer. The second gas sample is formed by eliminating ammonia from the gas sample. The method further includes measuring, by the hydrogen analyzer, an output signal for each of the first and second gas samples. The method includes calculating the amount of ammonia present in the gas sample based on the measured output signal for each of the first and second gas samples and a hydrogen error correction value.

Abstract: Tracing subterranean fluid flow includes providing a first polymeric tracer to a first injector, collecting a first aqueous sample from a first producer, and assessing the presence of the first polymeric tracer in the first aqueous sample. The first polymeric tracer includes a first polymer formed from at least a first monomer. The presence of the first polymeric tracer in the first aqueous sample is assessed by removing water from the first aqueous sample to yield a first dehydrated sample. pyrolyzing the first dehydrated sample to yield a first gaseous sample, and assessing the presence of a pyrolization product of the first polymer in the first gaseous sample. The presence of the pyrolization product of the first polymer in the first gaseous sample is indicative of the presence of a first subterranean flow pathway between the first injector location and the first producer location.

Abstract: Tracing subterranean fluid flow includes providing a first polymeric tracer to a first injector, collecting a first aqueous sample from a first producer, and assessing the presence of the first polymeric tracer in the first aqueous sample. The first polymeric tracer includes a first polymer formed from at least a first monomer. The presence of the first polymeric tracer in the first aqueous sample is assessed by removing water from the first aqueous sample to yield a first dehydrated sample. pyrolyzing the first dehydrated sample to yield a first gaseous sample, and assessing the presence of a pyrolization product of the first polymer in the first gaseous sample. The presence of the pyrolization product of the first polymer in the first gaseous sample is indicative of the presence of a first subterranean flow pathway between the first injector location and the first producer location.

Abstract: An explosive detection system for detecting explosive trace in a sample includes a detection unit, and a processing unit. The detection unit that receives a desorbed sample includes a first heater, a second heater, a first resistance temperature detector (RTD), a second RTD, and an amplifier. The first heater is exposed to the desorbed sample. The first heater and the second heater are supplied with specific voltage for three or more experiments. The first RTD and the second RTD measure changes in resistance due to heating of the first heater and the second heater to calculate voltages across the first RTD and the second RTD. The amplifier amplifies the voltages to calculate a differential voltage for each of the three or more experiments, and converts the differential voltage into a digital signal. The processing unit is configured to process the digital signal to detect explosive trace in the desorbed sample.

Abstract: A gas sensor system is for use in, or in the vicinity of, a toilet, for detecting a target gas. A gas sensor detects a concentration of at least the target gas and a further, reference, gas which is received from a controlled gas release device. These concentrations are processed to obtain a concentration of the target gas relative to the concentration of the further gas by combining a change in the detected concentration of the target gas, a change in the detected concentration of the further gas, the sensitivity of the gas sensor system to the target gas and the sensitivity of the gas sensor system to the further gas. This approach avoids the need for extensive calibration operations to tune the sensor response to the environment in which it is used.

Abstract: A chemosensing hydrogel is provided that undergoes a colorimetric reaction in response to the detection of a biogenic amine vapor, such as a biogenic amine vapor that is a by-product resulting from food spoilage. In an embodiment, an apparatus for detection of biogenic amines, is provided that includes a hydrogel having a bimetallic iron(II)-iron(III) complex disposed within the hydrogel, wherein the hydrogel is configured to change from a first color to a second color in response to exposure to a biogenic amine.

Abstract: Disclosed herein is an infrared emitter welder for fusion welding pipe joints. In one representative embodiment, the welder comprises a fuel tank adapted to contain a fuel under pressure and a heating element in fluid communication with the fuel tank. The heating element includes a pair of porous ceramic plates, each having opposing first and second surfaces, wherein the first surfaces of the ceramic plates are joined together, and wherein at least one of the first surfaces includes fuel distribution channels formed therein. A catalytic material, such as platinum, is disposed on at least one of the second surfaces and is operative to ignite the fuel as it reaches the second surface. A supply conduit interconnects the fuel tank and heating element.

Abstract: An apparatus for changing relative concentrations of first and second analyte substances in an analyte sample comprises a sample cell defining a sample chamber therewithin, and a semipermeable boundary member disposed in the sample chamber to define first and second sides of the sample chamber. Sample flow input and sample flow output ducts direct an analyte sample containing respective initial concentrations of the first and second analyte substances into the first side of the sample chamber. The semipermeable boundary member permits diffusion therethrough of the first and second analyte substances to the second side of the sample chamber at different rates. An analyte sample in the second side of the sample chamber, and an analyte sample exiting the first side via the sample flow output duct, have respective concentrations of the first and second analyte substances that are different from the initial concentrations.

Abstract: A sensing system for detecting a substance in a dialysate. The system includes a hydrophobic barrier capable of allowing the substance in the dialysate to equilibrate to a gas; a detector capable of detecting the gas; an interface disposed between the hydrophobic barrier and the detector and configured to allow fluid communication of the gas; and one or more delivery mechanisms capable of transporting the gas from the hydrophobic barrier to the detector. A method of detecting ammonium gas in a dialysate is also provided.

Abstract: An analytical device for analysis of chemical or biological samples, a method of using such a device, based on rotation of the device, integrated sample dosing and optical detection, and a system comprising such a device are disclosed. The analytical device comprises a device body having a liquid processing unit. The liquid processing unit comprises a mixing chamber for mixing a sample with a reagent, a sample dosing chamber for delivering a defined volume of the sample to the mixing chamber, and a reagent channel for delivering the reagent to be mixed with the sample, wherein the mixing chamber also serves as a detection chamber.

Abstract: An apparatus is provided for sensing an analyte in a fluid.

Abstract: A method that identifies the compounds contributing to a fish-like odor from an air conditioner and artificially reproduces the fish-like odor, and prepares a corresponding fish-like odor composition. Through the analysis method of the present invention, the compounds contributing to the fish-like odor from an air conditioner are identified and quantified. The fish-like odor is reproduced from a combination of the compounds identified by the analysis method of the present invention. The reproduced fish-like odor provides significant data required for development of an apparatus and a method for removing specific odor.

Abstract: A method is provided that identifies the compounds contributing to a malodor from an air conditioner, reproduces the malodor, and prepares a corresponding malodor composition. Through the analysis method of the present invention, the compounds contributing to the malodor from an air conditioner are identified and quantified. The malodor is reproduced from a combination of the compounds identified by the analysis method of the present invention. The reproduced malodor provides significant data required for development of an apparatus and a method for removing specific odor.

Abstract: In one aspect of the invention, a method includes determining an amount of carbon dioxide (CO2) in dialysate flowing through a dialysis system using a CO2 sensor associated with the dialysis system, determining, using a pH sensor associated with the dialysis system, a pH level of the dialysate, and calculating a level of bicarbonate in the dialysate based at least in part on the determined amount of CO2 measured in the gas and the determined pH level of the dialysate.

Abstract: Disclosed are methods and apparatus for treating and analyzing a gas stream to determine the effectiveness of urea gasification. The apparatus will be capable of performing the method and will include: means for introducing an aqueous solution of urea into a reactor having hot gases therein and subjecting the aqueous to temperatures for a time to assure the gasification of the aqueous urea and form a thermal gasification product stream containing NH3 and HNCO; means for taking a sample stream from the gasification product stream; means for contacting the sample stream with a hydrolysis catalyst in the presence of sufficient water to convert HNCO to NH3 and form an ammonia sample stream; and means for analyzing the ammonia sample stream for NH3. The methods and apparatus can also be used to control a urea gasification process and/or to signal anomalous operation.

Abstract: A method for modernizing an ammonia synthesis loop (1) with a first converter (10) and a second converter (11) in series, the first converter (10) comprises a cartridge with one or more catalyst beds, the second converter (11) comprises a catalyst bed in direct contact with said vessel, the method comprising the steps of removing the second converter, and boosting the first converter by replacing the cartridge with a high-efficiency cartridge comprising a plurality of adiabatic catalyst beds and inter-bed heat exchangers, or an isothermal catalyst bed, and by reducing the concentration of inerts in said first converter.

Abstract: An ammonia compound concentration measuring device includes: a pipe unit through which the circulating gas flows; a converter which is disposed in the pipe unit and converts an ammonia compound into ammonia; a measurement device which measures a first measurement value as a concentration of ammonia contained in a first circulating gas flowing inside a pipe line passing through the converter in the circulating gas flowing inside the pipe unit and a second measurement value as a concentration of ammonia contained in a second circulating gas flowing inside a pipe line not passing through the converter in the circulating gas flowing inside the pipe unit; and a controller which controls operations of the pipe unit and the measurement device and calculates the concentration of the ammonia compound of the measurement subject contained in the circulating gas from a difference between the first measurement value and the second measurement value.

Abstract: A chemical sensor comprising: a hydrogel layer, comprising one or more molecular recognition agents and a 2DPC self-assembling array; and a mirror layer. A method for analyzing a sample or bodily fluid, comprising: obtaining a sample or bodily fluid; placing an amount of the sample or bodily fluid onto a chemical sensor, comprising: a hydrogel layer, comprising a molecular recognition agent and a 2DPC self-assembling array; a tethering hydrogel layer; a mirror layer; and a membrane filter layer, allowing the bodily fluid to interact with the hydrogel layer; and allowing ambient or artificial light to pass through the hydrogel layer onto the mirror layer and observing a change in diffraction versus a control.

Abstract: Disclosed herein is a method for identifying compounds contributing to a sour odor emitting from an air conditioner, a method for artificially reproducing the detected sour odor and preparing a corresponding sour odor composition. Through the analysis method of the present invention, the compounds contributing to the sour odor emitted from an air conditioner may be identified and quantified. The detected sour odor may be reproduced from a combination of the compounds identified by the analysis method of the present invention. The reproduced sour odor may provide meaningful data required for development of an apparatus and a method for removing specific odors.

Abstract: An aquatic environment monitoring system and method that includes correction for adverse conditions in the monitoring system involving the development of confidence levels for certain conditions in the monitoring system using stored information related to the aquatic environment and/or the monitoring system. Corrections to adverse conditions may be made by the environment monitoring system automatically by the monitoring system and manually via communications to a user of the system.

Abstract: A microchannel chip having a microchannel formed in a substrate and a gas-liquid phase separation microchannel whose upper part is covered with a porous film, the gas-liquid phase separation microchannel being connected to the downstream end of the microchannel and having a depth of 10 ?m to 100 ?m. Also, a gas-liquid phase separation method which is a method for separating a liquid-phase flow from a two-phase flow flowing through a microchannel by removing a gas phase, the two-phase flow composed of the gas phase and the liquid phase, which liquid phase flows in the periphery of the above-described microchannel and which gas phase flows interiorly of the liquid-phase flow.

Abstract: A chemical indicator having a particulate inorganic substrate, and at least one reactive dye or ink coated on and/or impregnated within the particulate inorganic substrate. Coating and/or impregnating at least one reactive dye or ink on or within a particulate inorganic substrate improves the storage stability and/or thermal stability of the at least one reactive dye or ink, which typically includes relatively unstable compounds. This allows the present indicators to be incorporated into thermoplastic polymer materials and processed conventionally while maintaining the efficacy and stability of the new indicators. The indicators provide simple, reliable, and cost effective detection means for detecting analytes such as ammonia, carbon dioxide, and oxygen, and may find use in applications such as food packaging and medical applications.

Abstract: A method that identifies the compounds contributing to a fish-like odor from an air conditioner and artificially reproduces the fish-like odor, and prepares a corresponding fish-like odor composition. Through the analysis method of the present invention, the compounds contributing to the fish-like odor from an air conditioner are identified and quantified. The fish-like odor is reproduced from a combination of the compounds identified by the analysis method of the present invention. The reproduced fish-like odor provides significant data required for development of an apparatus and a method for removing specific odor.

Abstract: A gas sensor cell using a liquid crystal composite material is provided. The gas sensor cell has recovery capability and can be reused. Upon gas adsorption, the liquid crystal composite material has visually detectable color changes and changes in electrical properties to facilitate the measurement of gas concentration from low to high.

Abstract: A sensor, a method for its fabrication, and a method for its use to detect contaminants, for example, ammonia, in stagnant and dynamic fluid media, especially liquid media. The sensor is an opto-chemical sensor that includes a polymer optical fiber, a sensing layer comprising oxazine 170 perchlorate on the polymer optical fiber, and a membrane layer on the sensing layer. The membrane layer is gas permeable and not permeable to the fluid in the fluid system, and moisture is entrapped by and between the sensing and membrane layers.

Abstract: Disclosed herein is a method for identifying compounds contributing to a sour odor emitting from an air conditioner, a method for artificially reproducing the detected sour odor and preparing a corresponding sour odor composition. Through the analysis method of the present invention, the compounds contributing to the sour odor emitted from an air conditioner may be identified and quantified. The detected sour odor may be reproduced from a combination of the compounds identified by the analysis method of the present invention. The reproduced sour odor may provide meaningful data required for development of an apparatus and a method for removing specific odors.

Abstract: There are provided a method for analyzing an aqueous ammonium carbamate solution whereby the composition of an unreacted-gas absorber outlet liquid can be specified in real time, and a method for operating an unreacted gas absorber by use of the same.

Abstract: The invention relates to a device (10) for detection of harmful substances with a measurement unit (28) for measuring at least one harmful substance and an evaluation unit (30) for determining the concentration of the at least one harmful substance. The invention also relates to a method for detecting harmful substances in a gas mixture. It is hereby provided that the gas mixture is tested for a gaseous harmful substance or simultaneously for several gaseous harmful substances, wherein the gaseous harmful substance or the gaseous harmful substances is/are measured with different sensor means, and the gaseous harmful substances are optionally chemically modified such that a measurement is performed with the existing sensor means.

Abstract: A method for determining the amount of a chemical species in a sample, in particular the amount of weak acid dissociable cyanide or total cyanide in a sample, and an apparatus for performing said method. The method comprises the steps of: i) treating the sample to liberate the chemical species into a gaseous stream; ii) directing the gaseous stream to a scrubber; iii) absorbing the chemical species into a scrubber solution; and iv) determining the amount of chemical species absorbed into the scrubber solution, wherein any remaining chemical species not absorbed into the scrubber solution is directed or recirculated to the scrubber in the gaseous stream and step iii) is repeated to increase absorption of the chemical species prior to performing step iv).

Abstract: An ammonia compound concentration measuring device includes: a pipe unit through which the circulating gas flows; a converter which is disposed in the pipe unit and converts an ammonia compound into ammonia; a measurement device which measures a first measurement value as a concentration of ammonia contained in a first circulating gas flowing inside a pipe line passing through the converter in the circulating gas flowing inside the pipe unit and a second measurement value as a concentration of ammonia contained in a second circulating gas flowing inside a pipe line not passing through the converter in the circulating gas flowing inside the pipe unit; and a controller which controls operations of the pipe unit and the measurement device and calculates the concentration of the ammonia compound of the measurement subject contained in the circulating gas from a difference between the first measurement value and the second measurement value.

Abstract: N-(aminoacyl)-amino compound, represented by the following formula Wherein R1 denotes hydrogen, low alkyl or carbonyl, and N1 denotes an NH group and R2 denotes hydrogen or low alkylphenyl or aralkyl or imidazoalkyl or indolylalkyl, R1 and R2 together may complete a pyrrolidine or piperidine or thiazolidine ring and R3 denotes hydrogen or methyl or low alkyl and R4 denotes hydrogen or alkyl or the group remaining on exclusion of R4 from the formula and Z is a straight chain or branched alkylene, which may contain up to 3 carbon atoms. and R5 is nitrogen or sulphur or oxygen or salts thereof and ester compounds, characterised in that A is an ester or amino acid or alternatively sodium or a potassium salt of arginate and/or of ornithate and/or of aspharaginate.

Abstract: The present disclosure provides methods for evaluating daily ammonia exposure based on a single fasting ammonia blood level measurement, as well as methods that utilize this technique to adjust the dosage of a nitrogen scavenging drug, determine whether to administer a nitrogen scavenging drug, and treat nitrogen retention disorders.

Abstract: An ammonia gas sensing device includes a housing defining a fluid flow path. The fluid flow path includes a fluid inlet, a fluid outlet, and an access port. A gas permeable/liquid impermeable membrane is mounted on and sealed against the housing at the access port such that the membrane is exposed to the fluid flow path but fluid is blocked from flowing outward of the access port around rather than through the membrane. An ammonia sensor is mounted on the housing at the access port in a position outward of the membrane. A system for using the ammonia sensing device includes the ammonia gas sensing device, a light source directed at the ammonia sensor, a photo detector to measure the light reflected off the ammonia sensor from the light source, and a controller for controlling the light source and optical sensor.

Abstract: A sensor, a method for its fabrication, and a method for its use to detect contaminants, for example, ammonia, in stagnant and dynamic fluid media, especially liquid media. The sensor is an opto-chemical sensor that includes a polymer optical fiber, a sensing layer comprising oxazine 170 perchlorate on the polymer optical fiber, and a membrane layer on the sensing layer. The membrane layer is gas permeable and not permeable to the fluid in the fluid system, and moisture is entrapped by and between the sensing and membrane layers.

Abstract: The present invention relates to the field of detection of components in gas phase, and in particular to detection of nitric oxide exhaled as a component of breath, using a liquid crystal assay format and a device utilizing liquid crystals as part of a reporting system.

Abstract: Disclosed are methods and apparatus for treating and analyzing a gas stream to determine the effectiveness of urea gasification. The apparatus will be capable of performing the method and will include: means for introducing an aqueous solution of urea into a reactor having hot gases therein and subjecting the aqueous to temperatures for a time to assure the gasification of the aqueous urea and form a thermal gasification product stream containing NH3 and HNCO; means for taking a sample stream from the gasification product stream; means for contacting the sample stream with a hydrolysis catalyst in the presence of sufficient water to convert HNCO to NH3 and form an ammonia sample stream; and means for analyzing the ammonia sample stream for NH3. The methods and apparatus can also be used to control a urea gasification process and/or to signal anomalous operation.

Abstract: Sensors based on single-walled carbon nanotubes and graphene which demonstrate extreme sensitivity as reflected in their electrical conductivity to gaseous molecules, such as NO, NO2 and NH3, when exposed to in situ ultraviolet (UV) illumination during measurement of the analytes are disclosed. The sensors are capable of detection limits of NO down to almost 150 parts-per-quadrillion (“ppq”), detection limits of NO2 to 2 parts-per-trillion (“ppt”), and detection limits of NH3 of 33 ppt.

Abstract: A chemical indicator comprises a particulate inorganic substrate, and at least one reactive dye or ink coated on and/or impregnated within the particulate inorganic substrate. Coating and/or impregnating at least one reactive dye or ink on or within a particulate inorganic substrate improves the storage stability and/or thermal stability of the at least one reactive dye or ink, which typically comprises relatively unstable compounds. This allows the present indicators to be incorporated into thermoplastic polymer materials and processed conventionally while maintaining the efficacy and stability of the new indicators. The indicators provide simple, reliable, and cost effective detection means for detecting analytes such as ammonia, carbon dioxide, and oxygen, and may find use in applications such as food packaging and medical applications.

Abstract: A microchannel chip having a microchannel formed in a substrate and a gas-liquid phase separation microchannel whose upper part is covered with a porous film, the gas-liquid phase separation microchannel being connected to the downstream end of the microchannel and having a depth of 10 ?m to 100 ?m. Also, a gas-liquid phase separation method which is a method for separating a liquid-phase flow from a two-phase flow flowing through a microchannel by removing a gas phase, the two-phase flow composed of the gas phase and the liquid phase, which liquid phase flows in the periphery of the above-described microchannel and which gas phase flows interiorly of the liquid-phase flow.

Abstract: Vapochromic coordination polymers useful for analyte detection are provided. The vapochromism may be observed by visible color changes, changes in luminescence, and/or spectroscopic changes in the infrared (IR) signature. One or more of the above chromatic changes may be relied upon to identify a specific analyte, such as a volatile organic compound or a gas. The chromatic changes may be reversible to allow for successive analysis of different analytes. The polymer has the general formula MW[M?X(Z)Y]N wherein M and M? are the same or different metals capable of forming a coordinate complex with the Z moiety; Z is selected from the group consisting of halides, pseudohalides, thiolates, alkoxides and amides; W is between 1-6; X and Y are between 1-9; and N is between 1-5. One embodiment provides [Metal(CN)2]-based coordination polymers with vapochromic properties, such as Cu[Au(CN)2]2 and Zn[Au(CN)2]2 polymers.

Abstract: The present invention generally relates to methods for modulating the optical properties of a luminescent polymer via interaction with a species (e.g., an analyte). In some cases, the present invention provides methods for determination of an analyte by monitoring a change in an optical signal of a luminescent polymer upon exposure to an analyte. Methods of the present invention may be useful for the vapor phase detection of analytes such as explosives and toxins. The present invention also provides methods for increasing the luminescence intensity of a polymer, such as a polymer that has been photobleached, by exposing the luminescent polymer to a species such as a reducing agent.

Abstract: The invention provides a metal porous material, a method for preparing the same, and a method for detecting nitrogen-containing compounds. The method for fabricating metal porous material includes: mixing a siloxane, a metal or metallic compound, and water, to obtain a mixture after stirring; modifying the mixture to a pH value of less than 7; subjecting the mixture to a first dry treatment to obtain a solid; after polishing the solid to obtain a powder, subjecting the powder to a second dry treatment. It should be noted that the method is free of any annealing or calcination process.

Abstract: The present invention relates to chemical sensors with hybrid characteristics, which are thermo-mechanically stable and able to respond to changes in the environment, particularly in the presence of amine and/or amide and/or oxide-reducing compounds, and/or vapor thereof by color change, as well as its incorporation into sensitive polymeric composition.

Abstract: The invention relates to using heterobimetallic coordination polymers and their uses as chemodosimeters for sensing materials for the screening of specific biogenic amines.

Abstract: The present invention describes methods and kits for determining the concentration of free chlorine in water. To avoid false readings from other species present in the water, the free chlorine is reacted with ammonia to form monochloramine, which is then reacted to form an indophenol or an indonaphthol. The concentration of the indophenol or indonaphthol is proportional to the total monochloramine present. Subtracting the concentration of residual monochloramine from the total monochloramine yields the concentration of monochloramine formed from the free chlorine and ammonia, and is proportional to the concentration of free chlorine. Embodiments of the present invention will simplify and accelerate accurate measurements of free chlorine in water, without interference from compounds impacting present measurements of free chlorine.

Abstract: Disclosed are magnetic nanosensors or transducers that permit measurement of a physical parameter in an analyte via magnetic reasonance measurements, in particular of non-agglomerative assays. More particularly, in certain embodiments, the invention relates to designs of nanoparticle reagents and responsive polymer coated magnetic nanoparticles. Additionally provided are methods of use of nanoparticle reagents and responsive polymer coated magnetic nanoparticles for the detection of a stimulus or an analyte with NMR detectors.