The electrochemical behaviour of suspended nanoparticles received some attention recently. Very few studies are performed in the flow system. Here, we have demonstrated that injection of positively charged (with ammonium functionalities) carbon nanoparticles suspension to flowing ascorbic acid solution significantly enhances its chronoamperometric response and can be used for these nanoparticles detection. This is because of electrocatalytic properties of these nanoparticles towards ascorbic acid electrooxidation. The magnitude of the signal depends on the type of flow system and is larger than in the case of suspension of negatively charged nanoparticles. It is also proportional to the concentration of nanoparticles. Their adsorption on the electrode surface plays the crucial role in the electrode process.