New Tools for Characterizing Metallic Nanoparticles: AgNPs, A Case Study.

Currently, transmission electron microscopy (TEM) is the main technique for estimating the sizes of spherical nanoparticles (NPs) and through them, their concentrations. This paper demonstrates for the first time that C18 reversed-phase capillary liquid chromatography (Cap-LC) coupled to diode array detection (DAD) has the potential to estimate mean concentrations of silver nanoparticles (AgNPs) and thereby determine their average size. Direct injection of the sample without previous extraction or separation steps is carried out.

Microextraction with phases containing nanoparticles.

In this article, the state of the art of microextraction techniques that involve nanoparticles or nanomaterials (NPs) is reviewed, with special emphasis on the applications described in the biomedical field. The uses and advantages of the different types of NPs such as carbon nanotubes (either single- and multi-walled) and other carbon-based materials, metallic NPs, including gold, silver and magnetic NPs, and silica NPs are summarized. The main strategies used to modify the selectivity, extractive capacity and/or the stability of NPs through a chemical reaction are also reviewed.