A method uses an Dioleoylphosphatidylcholine (DOPC) surfactant based bio film that reacts with a material in a known manner, and a device that utilizes such a biofilm, to detect material of interest is provided. The principles of the present invention are particularly useful in detecting/measuring a material.

Technologies are generally described for gas filtration and detection devices. Example devices may include a graphene membrane and a sensing device. The graphene membrane may be perforated with a plurality of discrete pores having a size-selective to enable one or more molecules to pass through the pores. A sensing device may be attached to a supporting permeable substrate and coupled with the graphene membrane. A fluid mixture including two or more molecules may be exposed to the graphene membrane. Molecules having a smaller diameter than the discrete pores may be directed through the graphene pores, and may be detected by the sensing device. Molecules having a larger size than the discrete pores may be prevented from crossing the graphene membrane. The sensing device may be configured to identify a presence of a selected molecule within the mixture without interference from contaminating factors.

Detection of nitroxyl (HNO), the transient one-electron reduced form of nitric oxide, is a significant challenge owing to its high reactivity with biological thiols (rate constants as high as 10.sup.9M.sup.−1 s.sup.−1). Reported herein is a new thiol-based HNO-responsive trigger that can compete against reactive thiols for HNO. This process forms an N-hydroxysulfenamide intermediate which cyclizes to release a masked fluorophore leading to fluorescence enhancement. To ensure a rapid cyclization step, the disclosed design capitalizes on two established physical organic phenomena: the alpha-effect and the Thorpe-Ingold effect. Using this new trigger, NitroxylFluor was developed; a selective HNO-responsive fluorescent probe. Treatment of NitroxylFluor with an HNO donor results in a 16-fold turn-on. This probe also exhibits excellent selectivity over various reactive nitrogen, oxygen, and sulfur species and efficacy in the presence of thiols (e.g., glutathione in mM concentrations). Also, live cell imaging of HNO using NitroxylFluor was performed.

Detection of nitroxyl (HNO), the transient one-electron reduced form of nitric oxide, is a significant challenge owing to its high reactivity with biological thiols (rate constants as high as 10.sup.9M.sup.1 s.sup.1). Reported herein is a new thiol-based HNO-responsive trigger that can compete against reactive thiols for HNO. This process forms an N-hydroxysulfenamide intermediate which cyclizes to release a masked fluorophore leading to fluorescence enhancement. To ensure a rapid cyclization step, the disclosed design capitalizes on two established physical organic phenomena: the alpha-effect and the Thorpe-Ingold effect. Using this new trigger, NitroxylFluor was developed; a selective HNO-responsive fluorescent probe. Treatment of NitroxylFluor with an HNO donor results in a 16-fold turn-on. This probe also exhibits excellent selectivity over various reactive nitrogen, oxygen, and sulfur species and efficacy in the presence of thiols (e.g., glutathione in mM concentrations). Also, live cell imaging of HNO using NitroxylFluor was performed.

Detection reagent for an analyte comprising an NO.sub.x group, wherein the detection reagent comprises an arylamine, and a structural formula of the arylamine is selected from the structural formulae 1, 2 and 3:

##STR00001##

or of the formulae 4 or 5:

##STR00002##

where R.sub.1 and R.sub.7 are selected from CO.sub.2or PhCO.sub.2X with X=4-iodophenyl; 4-bromophenyl or 4-chlorophenyl; 4-vinylphenyl or 4-allylphenyl; or

R.sub.1 and R.sub.7 are selected from CO.sub.2Y or PhCO.sub.2Y with Y=2-methyl-3-pentyn-2-yl or 3-tert-butyl-4,4-dimethyl-1-pentyn-3-yl, or R.sub.7 is selected from CO.sub.2Z, PhCO.sub.2Z, C(O)NZ.sub.2 or PhC(O)NZ.sub.2 with (Z=alkyl, perfluoroalkyl, vinyl, allyl, homoallyl, aryl); where R.sub.2, R.sub.3, R.sub.4, and/or R.sub.5 are independently selected from H, F, an alkyl and an aryl; and where R.sub.6 is selected from an alkyl and an aryl.

Systems and methods related to optical nanosensors comprising photoluminescent nanostructures are generally described. Generally, the nanosensors comprise a photoluminescent nanostructure and a polymer that interacts with the photoluminescent nanostructure. In some cases, the interaction between the polymer and the nanostructure can be non-covalent (e.g., via van der Waals interactions). The nanosensors comprising a polymer and a photoluminescent nanostructure may be particularly useful in determining the presence and/or concentration of relatively small molecules, in some embodiments. In addition, in some instances the nanosensors may be capable of determining relatively low concentrations of analytes, in some cases determining as little as a single molecule. In some embodiments, the interaction between the analyte and the nanosensor (e.g., between the analyte and the photoluminescent nanostructure) can be reversible, which may allow, for example, for the reuse of a nanosensor after it has been exposed to an analyte.

A single device to collect, transfer, and measure salivary nitric oxide analyte and metabolite, nitrite, a biomarker for nitric oxide, as well as, a method to assess the effects of diet and exercise on changing an individual's nitric oxide status and health.

A single device to collect, transfer, and measure salivary nitric oxide analyte and metabolite, nitrite, a biomarker for nitric oxide, as well as, a method to assess the effects of diet and exercise on changing an individual's nitric oxide status and health.

Provided herein is technology relating to detecting gaseous analytes and particularly, but not exclusively, to devices and methods related to detecting gaseous analytes by monitoring changes in liquid crystals upon exposure to the gaseous analytes.

A single device to collect, transfer, and measure salivary nitric oxide analyte and metabolite, nitrite, a biomarker for nitric oxide, as well as, a method to assess the effects of diet and exercise on changing an individual's nitric oxide status and health.