'Nano-impacts': An Electrochemical Technique for Nanoparticle Sizing in Optically Opaque Solutions

Typical laser-dependent methods such as nanoparticle tracking analysis (NTA) and dynamic light scattering (DLS) are not able to detect nanoparticles in an optically opaque medium due to scattering or absorption of light. Here, the electrochemical technique of 'nano-impacts' was used to detect nanoparticles in solution in the presence of high levels of alumina particulates causing a milky white suspension. Using the 'nano-impacts' method, silver nanoparticles were successfully detected and sized in the model opaque medium. The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination. The ability to use the 'nano-impacts' method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach.