Preparation and characterization of ion-irradiated nanodiamonds as photoacoustic contrast agents

Chia Yi Fang, Cheng Chun Chang, Chung Yuan Mou, Huan Cheng Chang

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Highly radiation-damaged or irradiated nanodiamonds (INDs) are a new type of nanomaterial developed recently as a potential photoacoustic (PA) contrast agent for deep-tissue imaging. This work characterized in detail the photophysical properties of these materials prepared by ion irradiation of natural diamond powders using various spectroscopic methods. For 40-nm NDs irradiated with 40-keV He+ at a dose of 3 × 1015 ions/cm2, an average molar extinction coefficient of 4.2 M-1 cm-1 per carbon atom was measured at 1064 nm. Compared with gold nanorods of similar dimensions (10 nm x 67 nm), the INDs have a substantially smaller (by > 4 orders of magnitude) molar extinction coefficient per particle. However, the deficit is readily compensated by the much higher thermal stability, stronger hydrophilic interaction with water, and a lower nanobubble formation threshold (∼30 mJ/cm2) of the sp3-carbon-based nanomaterial. No sign of photodamage was detected after high-energy (> 100 mJ/cm2) illumination of the INDs for hours. Cell viability assays at the IND concentration of up to 100 μg/mL showed that the nanomaterial is non-cytotoxic and potentially useful for long-term PA bioimaging applications.

Original languageEnglish
Pages (from-to)1037-1044
Number of pages8
JournalJournal of Nanoscience and Nanotechnology
Issue number2
Publication statusPublished - Feb 1 2015
Externally publishedYes


  • Defect
  • Imaging
  • Irradiation
  • Nanoparticle
  • Photothermal spectroscopy

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • Biomedical Engineering
  • General Materials Science
  • Condensed Matter Physics


Dive into the research topics of 'Preparation and characterization of ion-irradiated nanodiamonds as photoacoustic contrast agents'. Together they form a unique fingerprint.

Cite this