Green Synthesis of Gold Nanoparticles Coupled with Nucleic Acid Oxidation

Tatsuki Kunoh, Minoru Takeda, Syuji Matsumoto, Ichiro Suzuki, Mikio Takano, Hitoshi Kunoh, Jun Takada

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


Green synthesis of metal nanoparticles, especially gold nanoparticles (AuNPs), has attracted the great interest of scientists and engineers in the medical and pharmaceutical fields; thus, a variety of ecofriendly, energy- and cost-saving techniques have been developed. In this study, we found that cells of Leptothrix (iron-oxidizing bacteria) released extracellular RNA some of which could exist as a constituent of the cell-enclosing sheaths. As a part of studies of metal encrustation in the sheaths, here we show that RNA prepared from the Leptothrix cells can reduce Au(III) and spherical AuNPs eventually form when an aqueous HAuCl4 solution is added under ambient conditions. RNA and DNA of other organismal origins have the same ability. Of the nucleosides and nucleobases, only guanosine and guanine can form AuNPs. The DNA moiety, 2′-deoxyguanosine (dG) (used as a reference material), forms AuNPs when mixed with HAuCl4 solution, but 8-hydroxy-2′-deoxyguanosine (8-OHdG) does not, indicating that AuNP formation evidently depends on the reduction potential of the guanine moiety, not the sugar moiety. This finding is the first demonstration that spherical AuNPs of ca. 5 nm diameter can be obtained by simply adding guanine to HAuCl4 solution at ambient temperature; no other chemicals or physical treatments are needed.

Original languageEnglish
Pages (from-to)364-373
Number of pages10
JournalACS Sustainable Chemistry and Engineering
Issue number1
Publication statusPublished - Jan 2 2018


  • 8-OHdG
  • Green synthesis of AuNPs
  • Guanine
  • Nucleic acid oxidation
  • Nucleic acids
  • RNA in Leptothrix sheaths

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Renewable Energy, Sustainability and the Environment


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