Impact electrochemistry: measuring individual nanoparticles.

While the electrochemistry of redox-active ions or molecules has been studied for decades, the electrochemistry of individual nanoparticles remains largely unexplored. In this issue of ACS Nano, Stuart et al. report the direct electrochemical detection of impacting carbon C60 nanoparticles in a non-aqueous solution. This study opens up the possibility of detecting and counting various redox-active inorganic, organic, and carbon-based nanoparticles, one by one, in colloids and suspensions by a simple and highly sensitive technique. The method developed by Stuart et al. enables the determination of the type, size, and concentration of the nanoparticles. One can foresee a wide scope of potential applications, ranging from the environmental monitoring of nanoparticles to the detection of self-propelled autonomous nano- and micromachines.