Preparation of Nucleic Acid Aptamer Functionalized Silver/Gold Nanoparticle Conjugates Using Thiol-Substituted Oligonucleotides

Silver and gold nanoparticle-aptamer conjugates have been extensively utilized as biosensors and microscopic vehicles that deliver a therapeutic cargo to cells. Here, we describe facile procedures to attach nucleic acid aptamers with a free thiol group to silver or gold nanoparticles. Methods to purify the nanoparticle-aptamer conjugates, verify aptamer attachment, and quantify aptamer-nanoparticle ratios are also discussed and compared. Additionally, a simple protocol that describes the aqueous synthesis of gold nanoparticles (~10 nm) is included.