Non-alloying core shell nanoparticles
View Patent ↗The present invention relates to composite core/shell nanoparticles and a two-step method for their preparation. The present invention further relates to biomolecule-core/shell nanoparticle conjugates and methods for their preparation. The invention also relates to methods of detection of biomolecules comprising the biomolecule or specific binding substance-core/shell nanoparticle conjugates.
1. A method for preparing core/shell nanoparticles comprising the steps of:
(a) providing inner metal-containing nanoparticle cores;
(b) treating the inner metal-containing nanoparticle cores simultaneously with a solution comprising a gold salt and a solution comprising a reducing agent at 0° C. to produce a non-alloying gold shell surrounding the nanoparticle cores; and
(c) isolating the core/shell nanoparticles.
2. The method according to claim 1 wherein the gold salt comprises HAuCl 4 , NaAuCl 4 , KAuCl 4 , or KAu(CN) 2 .
3. The method according to claim 1 wherein the gold salt comprises HAuCl 4 .
4. The method according to claim 1 wherein the reducing agent comprises NaBH 4 or ascorbic acid.
5. The method according to claim 4 wherein the reducing agent comprises NaBH 4 .
6. The method of claim 1 wherein in step (b) the gold salt and reducing agent form a reaction mixture having a gold salt concentration of about 2 uM.
7. The method of claim 1 wherein the inner metal-containing nanoparticle cores comprise a metal oxide, Fe, Ni, Co, FePt or FeAu.