Graphitic nanotubes in luminescence assays

摘要

Graphitic nanotubes, which include tubular fullerenes (commonly called “buckytubes”) and fibrils, which are functionalized by chemical substitution, are used as solid supports in electrogenerated chemiluminescence assays. The graphitic nanotubes are chemically modified with functional group biomolecules prior to use in an assay. Association of electrochemiluminescent ruthenium complexes with the functional group biomolecule-modified nanotubes permits detection of molecules including nucleic acids, antigens, enzymes, and enzyme substrates by multiple formats.

主权项

1. A method for detecting (i) a dehydrogenase enzyme that requires a nicotinamide adenine dinucleotide (NAD) cofactor or (ii) a substrate of said dehydrogenase enzyme present in a sample, the method comprising:
(a) forming an aqueous composition comprising (i) said sample; (ii) a graphitic nanotube attached to reacted bifunctional linker groups, each of the reacted bifunctional groups having first and second reacted groups, the first reacted group linked to a ruthenium label compound capable of being induced to luminesce and the second reacted group linked to an analog of the NAD cofactor selected from group consisting of NAD(P)+ and NAD(P)H, wherein said ruthenium label compound and said analog of the NAD cofactor are in contact; and (iii) said substrate of said dehydrogenase if the method is for detecting said dehydrogenase enzyme in the sample or said dehydrogenase enzyme if the method is for detecting said substrate of said dehydrogenase enzyme in the sample; (b) incubating said composition for a time suitable to form a complex and to allow the dehydrogenase enzyme to react with the substrate, wherein said complex comprises (i) said dehydrogenase enzyme or said substrate and (ii) said graphitic nanotube, and wherein said dehydrogenase enzyme is able to reduce or oxidize NAD(P)+ or NAD(P)H respectively in the presence of said substrate of said dehydrogenase; (c) inducing said ruthenium label compound in said complex to luminesce, wherein said NAD(P)+ and NAD(P)H have different abilities to cause luminescence of said ruthenium label compound; and (d) measuring luminescence emitted by said ruthenium label compound after step (c), wherein a change in luminescence indicates the detection of said dehydrogenase enzyme or said substrate in said sample.