Patent ID: 7186814

Claim:
A method for preparing a nanoparticle-probe, the nanoparticle-probe comprising a bioconjugate coupled to a nanoparticle, the method comprising: (i) reacting a thiol modifier reagent having a structure of formula: wherein n is 1–10, with a structure of formula: to produce a disulfide having the formula (ii) reducing the disulfides a″, b″, c″, d″ or e″ of (i) to produce a bioconjugate having formula: (iii) contacting one or more of the bioconjugates of (ii) with a nanoparticle to form the nanoparticle-probe, wherein the bioconjugate is coupled to the nanoparticle through the sulfur groups: wherein n is 2–100; m is 0–100; X is a nucleotide or modified nucleotide; Z is a nucleotide, modified oligonucleotide, or polyanion; Q is a recognition group; R is linear or branched C 1 –C 8 alkyl; W is a steroid; and each L is a linker formed by the coupling of two moieties selected from the group consisting of COOH, NH 2, CHO, F, Cl, Br, I, NCO, NCS, allyl, vinyl, and CH 3 CO 2 − , or L is —C(═NH 2 Cl)(CH 2 ) 3 —.