Colorimetric detection of DNA, small molecules, proteins, and ions using unmodified gold nanoparticles and conjugated polyelectrolytes

Fan Xia, Xiaolei Zuo, Renqiang Yang, Yi Xiao, Di Kang, Alexis Vallée-Bélisle, Xiong Gong, Jonathan D. Yuen, Ben B.Y. Hsu, Alan J. Heeger, Kevin W. Plaxco

Research output: Contribution to journalArticlepeer-review

430 Citations (Scopus)

Abstract

We have demonstrated a novel sensing strategy employing single-stranded probe DNA, unmodified gold nanoparticles, and a positively charged, water-soluble conjugated polyelectrolyte to detect a broad range of targets including nucleic acid (DNA) sequences, proteins, small molecules, and inorganic ions. This nearly "universal" biosensor approach is based on the observation that, while the conjugated polyelectrolyte specifically inhibits the ability of single-stranded DNA to prevent the aggregation of gold-nanoparticles, no such inhibition is observed with double-stranded or otherwise "folded" DNA structures. Colorimetric assays employing this mechanism for the detection of hybridization are sensitive and convenient - picomolar concentrations of target DNA are readily detected with the naked eye, and the sensor works even when challenged with complex sample matrices such as blood serum. Likewise, by employing the binding-induced folding or association of aptamers we have generalized the approach to the specific and convenient detection of proteins, small molecules, and inorganic ions. Finally, this new biosensor approach is quite straightforward and can be completed in minutes without significant equipment or training overhead.

Original languageEnglish
Pages (from-to)10837-10841
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume107
Issue number24
DOIs
Publication statusPublished - 2010 Jun 15

All Science Journal Classification (ASJC) codes

  • General

Fingerprint Dive into the research topics of 'Colorimetric detection of DNA, small molecules, proteins, and ions using unmodified gold nanoparticles and conjugated polyelectrolytes'. Together they form a unique fingerprint.

Cite this