Patent ID: 8221719

Claim:
A chelate comprising a lanthanide ion, Ln 3+ , selected from Eu 3+ , Sm 3+ , Tb 3+ and Dy 3+ , a chromophoric moiety, a chelating part comprising at least two carboxylic acid or phosphonic acid groups, or esters, amides or salts of said acids, attached to an aromatic unit of the chromophoric moiety, either directly or via a cyclic or acyclic N-containing hydrocarbon chain, a reactive group A, tethered to the chromophoric moiety or to the chelating part either directly or via a linker L, the reactive group A enabling binding to a biomolecule or to a functional group on a solid phase, wherein i) the reactive group A is selected from the group consisting of isothiocyanate, bromoacetamido, iodoacetamido, maleimido, 4,6-dichloro-1,3,5-triazin-2-ylamino, pyridyldithio, thioester, aminooxy, azide, hydrazide, amino, alkyne, a methacroyl group, and a carboxylic acid or acid halide or an active ester thereof or wherein A′ is a cleaving ligand selected from Cl, (CH 3 ) 2 SO, H 2 O, and NO 3 , and wherein -L is the position of linker L, ii) the linker L is formed from one to ten moieties, each moiety being selected from the group consisting of phenylene, alkylene containing 1-12 carbon atoms, ethynydiyl (—C≡C—), ethylenediyl (—C═C—), ether (—O—), thioether (—S—), amide (—CO—NH—, —CO—NR′—, —NH—CO— and —NR′—CO—), carbonyl (—CO—), ester (—COO— and —OOC—), disulfide (—SS—), sulfonamide (—SO 2 —NH—, —SO 2 —NR′—), sulfone (—SO 2 —), phosphate (—O—PO 2 —O—), diaza (—N═N—), and tertiary amine, wherein R′ represents an alkyl group containing less than 5 carbon atoms, iii) the chromophoric moiety comprises one or more aromatic units, wherein at least one of the aromatic units is a furyl or thienyl substituted pyridyl group, wherein the furyl or thienyl group is substituted with one or more, same or different, electron donating groups selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, sec-butyl, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, t-butoxy and sec-butoxy, and optionally with a carboxylic or sulfonic acid group, or with an ester, an amide or a salt of said acids, G, and wherein the aromatic units are tethered directly to each other to form a terpyridyl group, or are tethered to each other via a cyclic or an acyclic N-containing hydrocarbon chain.