Gold and silver quantification from gold-silver nanoshells in HaCaT cells

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Accurate elemental analysis of nanomaterials like gold (Au) and silver (Ag) nanoparticles is crucial for their application and safety.
• Existing methods may lack the sensitivity or robustness for complex matrices, including biological samples.

Purpose of the Study:

• To develop and validate a robust method for determining total Au and Ag concentrations in various nanostructures.
• To assess the method's performance, including accuracy, precision, and detection limits.
• To demonstrate the method's applicability in biological contexts, such as cellular uptake studies.

Main Methods:

• Samples (nanoparticles, Au-Ag nanoshells, silica-coated Au-Ag nanoshells) were mineralized using aqua regia and hydrofluoric acid.
• Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was employed for elemental analysis, with and without a collision/reaction cell (CRC).
• Method validation included recovery, Relative Standard Deviation (RSD) for repeatability, and determination of limits of detection (LOD) and quantitation (LOQ).

Main Results:

• High average recoveries of 99±2% for Au and 101±2% for Ag were achieved for nanopowders and test suspensions.
• Overall analytical RSD was ≤4%, with ICP-MS analysis RSD ≤2%, demonstrating excellent precision.
• LODs were as low as 0.005 μg/L for Au and 0.002 μg/L for Ag.
• The method successfully quantified elemental concentrations in biological media, with 70-100% recovery of nanoshells in cell culture experiments.

Conclusions:

• A validated ICP-MS method provides accurate and precise quantification of Au and Ag in nanomaterials.
• The method is robust and suitable for analyzing nanomaterials in complex biological matrices, including cellular uptake studies.
• The developed method enables reliable characterization of nanomaterials and assessment of their biological interactions.