The present invention relates to a sensor for dopamine-selective detection, a preparation method therefor, and use thereof.

The subject invention provides materials and methods for single-step detection of target molecules in a sample. The methods and assays of the subject invention employ a dye-displacement strategy, in which aptamers complexed with a cyanine dye for sensitive and rapid detection of targets of interest. In the presence of a target, aptamer-target binding liberates the non-covalently bound aptamer-binding dye, resulting in optical changes that can be observed spectrophotometrically or with the naked eye. The methods and assays of the subject invention enable the colorimetric detection of targets of interest regardless of their structure, sequence, target-binding affinity, and physicochemical properties of their targets.

This invention provides: —an aptamer-based electrochemical sensor, wherein said aptamer is covalently bonded to or chemisorbed on an electrode, said aptamer forming a complex with a target molecule and is encapsulated by a gelatin B matrix; —a method of manufacturing said aptamer-based electrochemical sensor; —the use of the aptamer-based electrochemical sensor for the electrochemical determination of a concentration of a target molecule; and —a composite electrode combining a polymeric material and electrically conducting particles for selective analyte detection, wherein said electrode is coated with gelatin type B.

Disclosed herein are a method and a kit using a novel marker associated with depression. The marker for depression includes one or more selected from a noradrenaline transporter and a dopamine transporter. The method for determining depression includes a step of examining an expression level of the marker for depression in a blood sample collected from a subject.

Embodiments described herein relate generally to compositions that include a synthetic redox-active receptor, and in particular to compositions that include a boronic acid based synthetic redox-active receptor which can electrochemically sense a target analyte in a sample solution. In some embodiments, a synthetic redox-active receptor can have a composition of formula I:

##STR00001##

wherein the variables L, L′, R, R′ n and X are described herein.

Disclosed is a method for simultaneous analysis of neurotransmitters and/or their metabolites. The method includes (a) separating analytes including a plurality of neurotransmitters and/or their metabolites from a sample selected from body tissues, body fluids, secretions, and excretions, (b) derivatizing the analytes with ethyl chloroformate to obtain derivatives of the plurality of neurotransmitters and/or their metabolites, (c) separating the derivatives of the plurality of neurotransmitters and/or their metabolites by liquid chromatography, and (d) subjecting the separated derivatives of the neurotransmitters or their metabolites to multiple reaction monitoring (MRM) using a mass spectrometer. According to the method, a plurality of neurotransmitters in a very small amount of sample can be simultaneously analyzed in an accurate and rapid manner based on derivatization to increase the stability and ionization efficiency of the substances.

The invention has for object an in vitro method for performing a differential diagnosis of neurodegenerative diseases selected from early stage of Alzheimer's disease, advanced stage of Alzheimer's disease, mental depression, dementia with Lewy bodies, frontotemporal dementia, and/or vascular dementia; said method being performed in a subject presenting signs of dementia and comprising the steps of (a) determining at least five criteria of said subject, said at least five criteria comprising the age of said subject, a score of said subject to a questionnaire adapted for screening cognitive function, a dopamine, adrenaline and noradrenaline concentration in a blood sample of said subject, (b) comparing said noradrenaline concentration to a predetermined threshold, (c) calculating one global note in relation with each neurodegenerative disease and (d) determining whether said subject suffers from one or more neurodegenerative diseases.

Methods, systems, compositions include biocompatible polymer coated nanoceria that function as aqueous redox catalyst with enhanced activity at an acidic to moderately alkaline pH value between 1 and 8. The compositions are used as oxidizing agents for decomposition, decontamination or inactivation of organic contaminants, such as, pesticides and chemical warfare agents. Another use includes nanoceria as targetable nanocatalyst prepared by conjugating various targeting ligands to the nanoparticle coating to form a colorimetric or fluorescent probe in immunoassays and other molecule binding assays that involve the use of a molecule in solution that changes the color of the solution or emits a fluorescent signal, where localization of nanoceria to organs or tissue is assessed by treatment with an oxidation sensitive dye or other detection devices. Versatility and uses of the nanoceria compositions are controlled by pH value, choice of dye substrate and thickness of the polymer coating on the ceria nanoparticles.

The subject invention provides materials and methods for single-step detection of target molecules in a sample. The methods and assays of the subject invention employ a dye-displacement strategy, in which aptamers complexed with a cyanine dye for sensitive and rapid detection of targets of interest. In the presence of a target, aptamer-target binding liberates the non-covalently bound aptamer-binding dye, resulting in optical changes that can be observed spectrophotometrically or with the naked eye. The methods and assays of the subject invention enable the colorimetric detection of targets of interest regardless of their structure, sequence, target-binding affinity, and physicochemical properties of their targets.

Provided herein are biosensors and methods for detecting one or more odorants associated with the levels, or a change in the levels, of one or more neurotransmitters in the central nervous system of a subject. In embodiments, provided are biosensors that comprise one or more populations of olfactory neurons, or cilia derived therefrom, wherein each population preferentially expresses a specific odorant receptor (OR). Also provided are biosensors comprising a cell or a population of cells engineered to express certain ORs; biosensors comprising certain isolated ORs; transgenic animals and tissues derived therefrom that preferentially express certain ORs; isolated cells or populations of cells engineered to express certain ORs; expression constructs for the preferential expression of certain ORs; and methods of using the biosensors, transgenic animals, tissues, cells, population of cells, and expression constructs disclosed herein.