Antibody-nanoparticle conjugates and methods for making and using such conjugates

摘要

Disclosed herein are antibody-nanoparticle conjugates that include two or more nanoparticles (such as gold, palladium, platinum, silver, copper, nickel, cobalt, iridium, or an alloy of two or more thereof) directly linked to an antibody or fragment thereof through a metal-thiol bond. Methods of making the antibody-nanoparticle conjugates disclosed herein include reacting an arylphosphine-nanoparticle composite with a reduced antibody to produce an antibody-nanoparticle conjugate. Also disclosed herein are methods for detecting a target molecule in a sample that include using an antibody-nanoparticle conjugate (such as the antibody-nanoparticle conjugates described herein) and kits for detecting target molecules utilizing the methods disclosed herein.

主权项

1. A method for detecting a target molecule in a sample, comprising:
(a) contacting the sample with a first antibody that specifically binds to the target molecule; (b) contacting the sample after step (a) with a second antibody conjugated to one or more enzyme molecules, wherein the second antibody specifically binds to the first antibody thereby forming a complex; (c) contacting the complex formed in step (b) above with a third antibody-nanoparticle conjugate wherein the third antibody specifically binds to the second antibody and wherein said third antibody-nanoparticle conjugate comprises three or more metal nanoparticles directly linked to a single third antibody through three or more metal-thiol bonds, wherein the metal-thiol bonds are between thiol of cysteine residues of the antibody and the three or more metal nanoparticles without an intervening linker; (d) contacting the sample after step (c) with a substrate of the enzyme and a metal ion, such that a metal precipitate forms and colocalizes with the target molecule; and (e) detecting the metal precipitate, thereby detecting the target molecule.