Diffusion limited green synthesis of ultra-small gold nanoparticles at room temperature

Maurizio Celentano*, Anshuman Jakhmola, Martina Profeta, Edmondo Battista, Daniela Guarnieri, Francesco Gentile, Paolo A. Netti, Raffaele Vecchione

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Synthesis of biocompatible and very stable ultra-small gold nanoparticles (Au-USNPs, 1–3 nm) by green methods has posed a challenge for a long time. The well-established Turkevich method involves naturally occurring reducing agents, like citrate, but it yields particles with a mean diameter ≥20 nm. Here, we extend the Turkevich method to the low nanometer range and enables the formation of Au-USNPs by implementing a diffusion limited mechanism. We attained tight control over the particle growth by carring the process (i) at room temperature and (ii) using micro-molar amounts of poly-vinyl-pyrrolidone (PVP) in (iii) conditions of Brownian motion. Particle size distribution along with UV–vis spectroscopy data confirm that particle growth is diffusion limited and can be explained by particle migration and coalescence model. Resulting nanoparticles display (i) very high stability, (ii) biocompatibility and (iii) functionalizable surface. These Au-USNPs may easily find applications in biomedical engineering, medicine, biotechnology and related fields.

Original languageEnglish
Pages (from-to)548-557
Number of pages10
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Early online date13 Sep 2018
Publication statusPublished - 05 Dec 2018
Externally publishedYes


  • Biocompatible
  • Diffusion limited
  • Gold nanoparticles
  • Highly stable
  • Polyvinylpirrolidone
  • Ultra-small

ASJC Scopus subject areas

  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

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