Bromide as a Robust Backfiller on Gold for Precise Control of DNA Conformation and High Stability of Spherical Nucleic Acids

Biwu Liu; Peng Wu; Zhicheng Huang; Lingzi Ma; Juewen Liu

doi:10.1021/jacs.8b01510

Bromide as a Robust Backfiller on Gold for Precise Control of DNA Conformation and High Stability of Spherical Nucleic Acids

J Am Chem Soc. 2018 Apr 4;140(13):4499-4502. doi: 10.1021/jacs.8b01510. Epub 2018 Mar 22.

Authors

Biwu Liu¹, Peng Wu², Zhicheng Huang¹, Lingzi Ma¹, Juewen Liu¹

Affiliations

¹ Department of Chemistry, Waterloo Institute for Nanotechnology , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada.
² Analytical & Testing Centre , Sichuan University , Chengdu 610064 , China.

PMID: 29561603
DOI: 10.1021/jacs.8b01510

Abstract

Functionalization of a gold surface with DNA is often complicated by kinetic traps from unintended DNA base adsorption. Herein, we communicate that Br^- serves as a robust backfilling agent displacing selected DNA bases on gold. Traditional thiol backfillers are too strong, while even 300 mM Br^- is well tolerated. Conjugates prepared with Br^- hybridize 10-fold faster and resist DNA release with better colloidal stability yielding highly sensitive probes. From colorimetric and Raman assays, adsorption affinity ranks as F^- < T ≈ Cl^- < C < G ≈ Br^- < A < I^-, allowing Br^- to displace nonpoly-A sequences from gold. This well-controlled biointerface will impact biosensing, drug delivery, and directed assembly of nanomaterials.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bromides / chemistry*
Colorimetry
Drug Stability
Gold / chemistry*
Metal Nanoparticles / chemistry
Models, Biological
Models, Molecular
Nanospheres / chemistry*
Nanostructures / chemistry*
Nucleic Acid Conformation
Nucleic Acids / chemistry*
Spectrum Analysis, Raman

Substances

Bromides
Nucleic Acids
Gold