Abstract: The present disclosure relates to compositions comprising quaternary metal chalcogenide nanoparticles stabilized by an inorganic metal-chalcogenide stabilizing agent, wherein the nanoparticles are dispersible in a polar solvent. More particularly, the disclosure relates to compositions of CZTS nanoparticles. This disclosure provides processes for manufacturing these compositions. The disclosure also provides coated substrates, thin films and devices comprising the compositions, and processes for manufacturing the same.

Abstract: A biosensor for detecting the presence of a target analyte is disclosed. The biosensor is formed from microspheroidal particles which have had a binding partner for the target analyte immobilized on their surfaces. The binding partners may be nucleotides; peptides, proteins, enzymes, antibodies and so on. When the analyte binds to its partner, the whispering gallery mode (WGM) profiles of the micro spheroidal particles change such that the profile peaks undergo a red- or blue-shift. The immobilized binding partners may include fluorophores and the like so that they emit fluorescence, phosphorescence, incandescence and the like. These fluorophores may take the form of a nanocrystal or quantum dot.

Abstract: A method of preparing an aqueous dispersion comprising silver particles of mean diameter from 0.5 to 25 nm by weight and an aqueous carrier liquid, including the steps of i) providing a mixture comprising at least one silver salt, aqueous carrier liquid and a stabiliser for the particles ii) contacting the mixture with a non-ionic or covalent reducing agent to form a reaction mixture iii) causing the at least one silver salt to react with the reducing agent to form a dispersion comprising silver particles and acid wherein step iii) is partly or completely performed in the presence of anion exchange resin whereby the acid is exchanged for a hydroxide ion from the resin and/or is sorbed by the resin.

Abstract: A rapid and sensitive analyte detection assay is based on whispering gallery modes of fluorescently labelled microspheroidal particles. Ligands for the analyte, such as nucleic acids, are anchored to the particles. The fluorescent labels may comprise fluorophores or quantum dots. In the latter case, the particles may comprise melamine formaldehyde. The assay may be used to detect analytes in aqueous samples.

Abstract: A method for the production of an inorganic film on a substrate, the method comprising: (a) depositing a layer of nanoparticles on the substrate by contacting the substrate with a nanoparticle dispersion; (b) treating the deposited layer of nanoparticles to prevent removal of the nanoparticles in subsequent layer depositing steps; (c) depositing a further layer of nanoparticles onto the preceding nanoparticle layer on the substrate; (d) repeating treatment step (b) and deposition step (c) at least one further time; and (e) optionally thermally annealing the multilayer film produced following steps (a) to (d); wherein the method comprises at least one thermal annealing step in which the layer or layers of nanoparticles are thermally annealed.

Abstract: A biosensor for detecting the presence of a target analyte is disclosed. The biosensor is formed from microspheroidal particles which have had a binding partner for the target analyte immobilized on their surfaces. The binding partners may be nucleotides; peptides, proteins, enzymes, antibodies and so on. When the analyte binds to its partner, the whispering gallery mode (WGM) profiles of the micro spheroidal particles change such that the profile peaks undergo a red- or blue-shift. The immobilized binding partners may include fluorophores and the like so that they emit fluorescence, phosphorescence, incandescence and the like. These fluorophores may take the form of a nanocrystal or quantum dot.

Abstract: A method of preparing an aqueous dispersion comprising metal particles of mean diameter from 0.5-200 nm by weight and an aqueous carrier liquid, including the steps of i) providing a mixture comprising at least one metal salt, aqueous carrier liquid and a stabilizer for the particles ii) contacting the mixture with a reducing agent to form a reaction mixture iii) causing the at least one metal salt to react with the reducing agent to form a dispersion comprising metal particles and acid wherein step iii) is partly or completely performed in the presence of anion exchange resin whereby the acid is exchanged for a hydroxide ion from the resin and/or is sorbed by the resin.

Abstract: A method of preparing an aqueous dispersion comprising silver particles of mean diameter from 0.5 to 25 nm by weight and an aqueous carrier liquid, including the steps of i) providing a mixture comprising at least one silver salt, aqueous carrier liquid and a stabiliser for the particles ii) contacting the mixture with a non-ionic or covalent reducing agent to form a reaction mixture iii) causing the at least one silver salt to react with the reducing agent to form a dispersion comprising silver particles and acid wherein step iii) is partly or completely performed in the presence of anion exchange resin whereby the acid is exchanged for a hydroxide ion from the resin and/or is sorbed by the resin.

Abstract: A rapid and sensitive analyte detection assay is based on whispering gallery modes of fluorescently labelled microspheroidal particles. Ligands for the analyte, such as nucleic acids, are anchored to the particles. The fluorescent labels may comprise fluorophores or quantum dots. In the latter case, the particles may comprise melamine formaldehyde. The assay may be used to detect analytes in aqueous samples.

Abstract: A biosensor for detecting the presence of a target analyte is disclosed. The biosensor is formed from microspheroidal particles which have had a binding partner for the target analyte immobilized on their surfaces. The binding partners may be nucleotides; peptides, proteins, enzymes, antibodies and so on. When the analyte binds to its partner, the whispering gallery mode (WGM) profiles of the microspheroidal particles change such that the profile peaks undergo a red-or blue-shift. The immobilised binding partners may include fluorophores and the like so that they emit fluorescence, phosphorescence, incandescence and the like. These fluorophores may take the form of a nanocrystal or quantum dot.