Detection of single Au nanoparticle collisions using electrocatalytic amplification method

Detection of single gold (Au) nanoparticle (NP) collisions on a carbon-fiber (C-fiber) ultramicroelectrode (UME) was carried out successfully using the electrocatalytic amplification method. The C-fiber UME shows a low and quite stable background current for the hydrazine oxidation over a wide potential range. The electrocatalytic current transient generated by Au NP collision on the C-fiber UME was also detected simultaneously without any pretreatment of the UME or deformation of the Au NP. The magnitude and frequency of the transient current from Au NP collisions agree well with the calculated values based on the size and concentration of the Au NP