Continuous Electrochemical Detection of Gold Nanoparticles in Flow

Nanoparticles have already found numerous applications and their global production is still increasing. Therefore, the engineered nanoobjects of uncertain toxicity become ubiquitous in the environment and a continuous monitoring of their presence is highly desirable. Here, we demonstrate a continuous electrochemical detection of gold nanoparticles (AuNPs) based on synchronous processes of their electrodissolution and electrocatalysis. This approach is realized by the injection of nanoparticles suspension into the Flow Injection Analysis (FIA) system. The modular structure of FIA system is particularly applicable for carrying out of sequential operations: AuNPs passivation, oxidation of aqueous SO2 and gold. It enables continuous, fast and reproducible gold nanoparticles determination in a wide concentration range: 10−10– 10−7 mol nanoobjects L−1.