Salicylamide-lanthanide complexes for use as luminescent markers

1. A luminescent complex formed between a lanthanide ion and a compound having a structure according to Formula I:

wherein,

R 1 and R 2 are members independently selected from the group consisting of alkyl, substituted alkyl, polyether, substituted polyether, halogen and —OR 6 , wherein

R 6 is a member selected from the group consisting of H, alkyl, substituted alkyl groups, polyether, substituted polyether, and a single negative charge;

R 4 , R 5 , R 7 , R 10 and R 20 are members independently selected from the group consisting of H, polyether, substituted polyether, alkyl and substituted alkyl groups;

R 3 , R 8 and R 9 are members independently selected from the group consisting of polyether, substituted polyether, alkyl and substituted alkyl groups;

R 11 , R 12 , R 13 , R 21 , R 22 and R 23 are members independently selected from alkyl, substituted alkyl, H, —NR 14 R 15 , —NO 2 , —OR 16 , —COOR 17 ,

wherein, R 14 , R 15 , R 16 and R 17 are members independently selected from the group consisting of H, alkyl and substituted alkyl, wherein R 12 can optionally form a ring with R 11 , R 13 or both, and R 22 can optionally form a ring with R 21 , R 23 or both, said rings being members independently selected from the group of ring systems consisting of cyclic alkyl, substituted cyclic alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclyl and substituted heterocyclyl ring systems; and

Q 1 is —OR 18 ;

Q 2 is —OR 19 ,

wherein R 18 and R 19 are members independently selected from H, an enzymatically labile group, a hydrolytically labile group and a single negative charge; and

a and z are independently selected from the group consisting of 0 and 1, with the proviso that when a is 0, N 1′ is covalently attached directly to carbonyl 1′, and

when z is 0, N 2′ is covalently attached directly to carbonyl group

wherein said compound is covalently attached to a member selected from a receptor and a drug.

2. The complex of claim 1 , wherein said drug is a member selected from non-steroidal anti-inflammatory drugs, antihistaminic drugs, antitussive drugs, antipruritic drugs, anticholinergic drugs, anti-emetic drugs, antinauseant drugs, anorexic drugs, central stimulant drugs, antiarrhythmic drugs, β-adrenergic blocker drugs, cardiotonic drugs, antihypertensive drugs, diuretic drugs, vasodilator drugs, vasoconstrictor drugs, antiulcer drugs, anesthetic drugs, antidepressant drugs, tranquilizer and sedative drugs, antipsychotic drugs, antimicrobial drugs, antineoplastic drugs, cytocidal agents, anti-estrogens, and antimetabolites.

3. The complex of claim 2 , wherein said receptor interacts with said drug.

4. A method of performing a fluorescence assay of a drug, said method comprising:

(a) displacing with said drug a binding partner from a binding partner-receptor complex, thereby forming an drug-receptor complex and a free binding partner, said binding partner and said free binding partner comprising a compound according to claim 1 ;

(b) forming a fluorescent complex between a lanthanide ion and a member selected from the group consisting of said binding partner, said free binding partner and combinations thereof; and

(c) detecting said fluorescent complex.

5. The method according to claim 4 , wherein one or more members selected from the group consisting of said receptor, said binding partner and said drug are attached to a surface.

6. The method according to claim 4 , wherein said fluorescent complex is formed prior to displacing said binding partner from said binding partner-receptor complex.

7. The method according to claim 4 , wherein said fluorescent complex is formed after displacing said binding partner from said binding partner-receptor complex.

8. The method according to claim 4 , further comprising, separating said free binding partner from a member of the group consisting of said receptor-binding partner pair, said drug-receptor pair and combinations thereof.

9. The method according to claim 8 , wherein said fluorescent complex is formed following said separation.