title: A method of measuring gold nanoparticle concentrations by X-ray fluorescence for biomedical applications.
abstract: OBJECTIVE
  This paper reports a technique that enables the quantitative determination of the concentration of gold nanoparticles (GNPs) through the accurate detection of their fluorescence radiation in the diagnostic x-ray spectrum.
  
  
  METHODS
  Experimentally, x-ray fluorescence spectra of 1.9 and 15 nm GNP solutions are measured using an x-ray spectrometer, individually and within chicken breast tissue samples. An optimal combination of excitation and emission filters is determined to segregate the fluorescence spectra at 66.99 and 68.80 keV from the background scattering. A roadmap method is developed that subtracts the scattered radiation (acquired before the insertion of GNP solutions) from the signal radiation acquired after the GNP solutions are inserted.
  
  
  RESULTS
  The methods effectively minimize the background scattering in the spectrum measurements, showing linear relationships between GNP solutions from 0.1% to 10% weight concentration and from 0.1% to 1.0% weight concentration inside a chicken breast tissue sample.
  
  
  CONCLUSIONS
  The investigation demonstrated the potential of imaging gold nanoparticles quantitatively in vivo for in-tissue studies, but future studies will be needed to investigate the ability to apply this method to clinical applications.
authors: Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA.
authors: Di
authors: D
authors: Wu
authors: Yuhua
authors: Y
authors: Li
authors: Molly D
authors: MD
authors: Wong
authors: Hong
authors: H
authors: Liu
mesh_terms: D000818:Animals; D002138:Calibration; D002645:Chickens; D006046:Gold / Q000737:chemistry* / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D057054:Molecular Imaging / Q000379:methods*; D011522:Protons; D013052:Spectrometry, X-Ray Emission
chemical_list: D011522:Protons; D006046:Gold