Generation of reactive oxygen species induced by gold nanoparticles under x-ray and UV Irradiations

Masaki Misawa*, Junko Takahashi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

269 Citations (Scopus)


The radiosensitizing effect of 5--250 nm diameter Au nanoparticles (AuNPs) in water was investigated under irradiations of diagnostic x-ray and UV light. Enhanced generations of hydroxyl radical ( OH) and superoxide anion (O 2 -) were confirmed from their dependencies on the absorbed energy, ethanol concentration and AuNPs' concentration. Two kinds of fluorescent probes revealed that the reactive oxygen species (ROS) generation rate under x-ray irradiation was enhanced by factors of 1.46 for OH and 7.68 for O 2 -. Photo- and Auger electron charge transfer is possibly relevant to generation of O 2 - near the particle surface, whereas fluorescent x-rays are involved in generation of OH in the secondary water radiolysis. Smaller diameter AuNPs with larger surface area showed a greater yield of ROS. An inverse proportion of ROS generation to the AuNPs' diameter suggests a catalytic function of AuNPs' surface for enhanced ROS generation. From the Clinical Editor: This paper investigates the effects of UV and X-ray irradiation on reactive oxygen species induction of gold nanoparticles, concluding that smaller diameter AuNPs with larger surface area lead to a greater yield of ROS probably due to catalytic effects. The paper may be important for the development of novel non-toxic radiation sensitizers.

Original languageEnglish
Pages (from-to)604-614
Number of pages11
JournalNanomedicine: Nanotechnology, Biology, and Medicine
Issue number5
Publication statusPublished - 2011 Oct
Externally publishedYes


  • Gold nano particles
  • Radiolysis
  • Radiosensitizer
  • Reactive oxygen species
  • X-ray

ASJC Scopus subject areas

  • Bioengineering
  • Medicine (miscellaneous)
  • Molecular Medicine
  • Biomedical Engineering
  • Materials Science(all)
  • Pharmaceutical Science


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