Open AccessThermodynamically Controlled Separation of Polyvalent 2-nm Gold Nanoparticle-Oligonucleotide Conjugates
Author(s) -
Jae Seung Lee,
Dwight S. Seferos,
David A. Giljohann,
Chad A. Mirkin
Publication year - 2008
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/ja800797h
Subject(s) - chemistry , dna , oligonucleotide , nanoparticle , colloidal gold , yield (engineering) , nucleic acid thermodynamics , centrifugation , conjugate , nanotechnology , chemical engineering , chromatography , biochemistry , base sequence , mathematical analysis , materials science , mathematics , engineering , metallurgy
We describe the synthesis of small (2-nm diameter) gold nanoparticles densely functionalized with thiolated DNA (DNA-Au NPs) and a method to separate these particles from excess free DNA after synthesis. The separation method utilizes the thermodynamically enhanced binding properties of 2-nm DNA-Au NPs, compared to free excess DNA, to selectively hybridize these small particles to larger (15-nm diameter) DNA-Au NPs and form aggregates that can be isolated by simple centrifugation. These 2-nm DNA-Au NPs are obtained in a 46% overall yield, have a high surface coverage of DNA (64.8 +/- 6.4 pmol/cm2), and as a result, exhibit increased melting temperatures and cooperative melting properties.