Abstract: The invention provides an electrochemical assay for a phenol analyte in a body fluid sample wherein said sample, or fluid therefrom, is contacted with the working electrode of an electrode assembly comprising a working electrode, a counter-electrode, a voltage supply to said working and counter-electrodes and a current meter for determining the current between said working and counter-electrodes, and wherein a first compound capable of reversible oxidation and reduction is disposed at said working electrode, said first compound being capable in either an oxidized or a reduced form of binding to said phenol analyte, characterized in that said first compound in its oxidized or reduced form comprises a group of structure I R1-NH—C*—(C*—C*)n—C*-QR? (I) (where n is 0 or 1; Q is 0, S, NH or NR?; C*—(C*—C*)n—C* is a two or four carbon string in a conjugated delocalised electron system optionally substituted by a group comprising R; R is an electron-donating or withdrawing substituent; and R? is H or a group R, at le

Abstract: The invention provides a method of assaying for tetrahydrocannabinol in a body fluid. The method includes contacting a sample of body fluid with an imine capable of reacting with tetrahydrocannabinol to yield a quinone imine, and detecting the formation of a quinone imine, where the sample is contacted with the reagent compound at a pH of at least 10.5.

Abstract: According to the present invention, phenols may be detected using an electrochemical sensor comprising a first compound, a working electrode and an electrolyte in contact with the working electrode, wherein the first compound operatively undergoes a redox reaction at the working electrode to form a second compound which operatively reacts in situ with the phenol, wherein said redox reaction has a detectable redox couple and wherein the sensor is adapted to determine the electrochemical response of the working electrode to the consumption of said second compound on reaction with the phenol. The phenol may be, for example, a cannabinoid or a catechin compound.

Abstract: The invention provides an assay method for the detection of a primary amine analyze in an aqueous body fluid, which method comprises contacting a sample of said body fluid at a pH below 9.5 with a thiol and an unsaturated cis-dialdehyde and testing for the presence of a pyrrole reaction product.

Abstract: The invention provides an electrochemical sensor comprising an electrode assembly which comprises at least two electrodes, one of the electrodes comprising a metal species capable of catalysing the oxidation of hydrogen and/or methane. The sensor may be used in the detection and quantification of hydrogen and/or methane in exhaled breath, for example as a means of diagnosing lactose malabsorption or lactose intolerance.

Abstract: The invention provides a method of assaying for tetrahydrocannabinol in a body fluid, said method comprising contacting a sample of body fluid with an imine capable of reacting with tetrahydrocannabinol to yield a quinone imine, and detecting the formation of a quinone imine, characterised in that said sample is contacted with said reagent compound at a pH of at least 10.5.

Abstract: The invention provides an assay method for the detection of a primary amine analyte in an aqueous body fluid, which method comprises contacting a sample of said body fluid at a pH below 9.5 with a thiol and an unsaturated cis-dialdehyde and testing for the presence of a pyrrole reaction product.

Abstract: The invention provides an electrochemical assay for a phenol analyte in a body fluid sample wherein said sample, or fluid therefrom, is contacted with the working electrode of an electrode assembly comprising a working electrode, a counter-electrode, a voltage supply to said working and counter-electrodes and a current meter for determining the current between said working and counter-electrodes, and wherein a first compound capable of reversible oxidation and reduction is disposed at said working electrode, said first compound being capable in either an oxidized or a reduced form of binding to said phenol analyte, characterized in that said first compound in its oxidized or reduced form comprises a group of structure I R1-NH—C*—(C*—C*)n—C*-QR? (I) (where n is 0 or 1; Q is 0, S, NH or NR?; C*—(C*—C*)n—C* is a two or four carbon string in a conjugated delocalised electron system optionally substituted by a group comprising R; R is an electron-donating or withdrawing substituent; and R? is H or a group R, at le

Abstract: There is provided a method of detecting an analyte in a sample, which comprises the steps of contacting the sample with a working electrode in the presence of an electrolyte and determining the electrochemical response of the working electrode to the sample, wherein the working electrode comprises a multi-walled carbon nanotube (MWCNT) and wherein detection takes place in the presence of a species which is capable of forming an intercalation compound with a carbon host material. Electrochemical sensors and compositions suitable for use in said method are also provided.

Abstract: An electrochemical sensor and method of detecting gaseous analytes are provided, which involve the use of a working electrode comprising edge plane pyrolytic graphite.

Abstract: According to the present invention, phenols may be detected using an electrochemical sensor comprising a final compound, a working electrode and an electrolyte in contact with the working electrode, wherein the first compound operatively undergoes a redox reaction at the working electrodes to form a second compound which operatively reacts in situ with the phenol, wherein said redox reaction has a detectable redox couple and wherein the sensor is adapted to determine the electrochemical response of the working electrode to the consumption of said second compound on reaction with the phenol. The phenol may be, for example, cannabinoid or a catechin compound.