Quantification of gold nanoparticles in blood using total reflection X-ray fluorescence

Abstract

The interactions of gold nanoparticles (AuNPs) with blood represents the first systemic clearance barrier that these particles face in-vivo. Assessment of this interaction is of particular interest in evaluating the efficacy and kinetics of AuNP delivery in various tissues or organs. Total reflection X-ray fluorescence (TXRF) spectroscopy offers multielemental quantification of trace-level concentrations through internal standardization. In this work, we investigate different sample preparation procedures to determine an appropriate method that would allow accurate quantification of AuNPs in blood matrix. Whole blood, plasma and red blood cells samples were doped with La internal standard and certified Au solution. The samples were prepared as is and diluted with water in ratios of 1:1, 1:5 and 1:10. In order to extend the investigation to AuNPs, samples were also doped with 10 nm reference material AuNPs and diluted with aqua regia in ratios of 1:1, 1:5, 1:10. Our results demonstrate that near 100% recovery of Au concentration can be obtained with the appropriate dilutant and dilution ratio. This work facilitates TXRF's transition into AuNP research as it offers an easy-to-use analytical toolbox that can accurately quantify AuNPs in blood.