A simple spectroscopic method for the quantification of gold nanoparticle number concentration in water and fetal bovine serum solutions

Abstract

In this work, we developed a facile and low-cost method with sufficient sensitivity for the quantitative determination of gold nanoparticles (GNPs) number concentration in water and fetal bovine serum solutions. The Au(III) digested from GNPs was reduced to Au(I) presumably by the thiol group of 2-mercaptobenzimidazole, then the Au(I)–thiolate complex was formed, the concentration of which is determined by absorbance at 300 nm. The number concentration of GNPs can be converted using microscopic images and simple calculations. The interference of serum can be avoided in this method. The limit of detection (LOD) of GNPs was calculated as 2.1 × 10−12 mol/L in water solution and 1.3 × 10−11 mol/L in fetal bovine serum (FBS) solution. This method provides a simple and fast way to determine the concentration of GNPs, which can be in carried out in the routine laboratory practice.