Anodic particle coulometry (APC) has great potential in probing the size, size distribution, and degree of aggregation of nanoparticles. However, one of the current challenges in APC is the relatively poor sensitivity to large particle aggregates, which may hinder its wide applications. Here we present a simple and effective way to count comprehensively collisional signals on an inverted carbon ultramicroelectrode, by electrochemical oxidation of gold nanoparticles or large particle aggregates in 0.04 M HCl with and without 0.02 M NaCl, respectively. The results of collision experiments are well consistent with those obtained from dynamic light scattering, indicating the retrieval of the lost information of the aggregated particles due to the detrimental gravity effect. Our work has achieved the simultaneous determination of single nanoparticle and aggregated nanoparticles, and thus further expands the applicable range of APC.