Compounds and Methods for Use in Detecting Gabapentin

A method for detecting the presence or absence of gabapentin in a sample, said method comprising:

• (a) adding, to a reaction mixture, (i) a biological sample and (ii) an anti-gabapentin antibody capable of forming of a complex of gabapentin that may be present in the sample and the antibody;
• and
• (b) detecting the presence or absence of the complex;
• wherein the presence or absence of said complex is indicative of the presence or absence of gabapentin in said sample.

A gabapentin immunoassay kit comprising:

• an anti-gabapentin antibody;
• and
• a gabapentin conjugate having the structure:
• wherein:
• R1, R2, or R3 is —X—W-L-Z,
• when R1 is —X—W-L-Z, X is NH, and R2 is —OH, and R3 is —H,
• when R2 is —X—W-L-Z, X is NH, R1 is —NH2, and R3 is —H, and
• when R3 is —X—W-L-Z, X is a heteroatom or lower alkyl group, R1 is —NH2, and R2 is —OH;
• W is a lower alkyl group or a carbonyl group;
• L is a linker or at least one bond between W and Z;
• and
• Z is H, an alkyl group, a reactive functional group capable of reacting with a reactive partner to form a covalent bond, or a moiety of interest, or a salt thereof,
• wherein the anti-gabapentin antibody is capable of forming a complex of the gabapentin conjugate and the antibody and of gabapentin that may be present in a biological sample and the antibody.