Observation of Blip Response in a Single Pt Nanoparticle Collision on a Cu Ultramicroelectrode

The collision of a single Pt nanoparticle (NP) was observed by an electrocatalytic amplification method. A Au ultramicroelectrode (UME) is usually used for the detection of Pt single NP collisions. The transient current response of the colliding Pt NP with the Au UME was observed as a staircase response. However, the response of the transient current by NP collision is affected by various factors including the material of the UME. In this study, a Cu UME was employed for the detection of a single Pt NP collision to investigate the effect of the UME material on the current response. A different current response, namely a blip response, was obtained by using Cu UME unlike the other UMEs. The peak height and collision frequency were analyzed and compared with the previous results using Au, Hg, or Ni UME for a better understanding of the UME material's effect on single Pt NP collision.