Electrochemical response of catalytic nanoparticles in Flow Injection Analysis system

Continuous Electrochemical Detection of Gold Nanoparticles in Flow

“…The response and reproducibility on a single ITO electrode (blue points in Figure ) is similar to those with the disposable ITO electrodes (red points in Figure ). This suggests that a memory‐effect of electrode does not appear at all , and AuNPs desorb from the electrode surface. Moreover, the shape of the current‐time dependence (Figure ) indicates a lack of sensitivity loss in time.…”

“…Although mechanism of this process is quite complex, we will demonstrate that such synergy significantly enhances the magnitude of the signal. It allows an increase of amperometric signal, but also eliminates a memory‐effect caused by irreversible adsorption earlier seen with carbon nanoparticles . We also tested the electrooxidation of AuNPs in acidic solutions containing more difficult to oxidize chloride and bromide ions accelerating gold dissolution , , .…”

“…However, mathematical descriptions of transport and dispersion of analysed sample in flow injection analysis systems are typically very complex and their creation requires the use of numerical techniques or flow models. It has to be emphasized that flow system with electrochemical detection based only on the direct impacts or electrocatalytic process were earlier successfully employed to detection of silver and carbon nanoparticles , respectively.…”

Electrochemical Detection of Positively Charged Carbon Nanoparticles Suspension in Flow

“…Recently, we and others demonstrated that it is possible to record the amperometric response of the catalytic nanoparticles from the background current on standard size disc electrodes (diameter in the range of millimetres) in forced convection conditions. This was done in both flow system and with rotating disc electrode . It was concluded, that adsorption of catalytic nanoparticles provides suitable conditions for discrimination of the faradaic from capacitive current.…”

“…This is the case of mixed film of positively (CNPs + ) and negatively (CNPs − ) charged carbon nanoparticles or CNPs + deposited on MoS 2 nanopetal stacks . Earlier studies in flow system were performed with suspended CNPs − either on bare indium tin oxide (ITO) electrodes or modified with positively charged functionalities . Here we will show that suspended CNPs + promote larger enhancement of the amperometric signal related to the ascorbate (AA) electrooxidation at ITO electrode as compared to CNP − .…”