Deposition of gold nanoparticles is varied by different scales of various surface patterns on 3D printed electrodes

Fused Filament Fabrication (FFF) has provided the unique ability make electrochemical sensors with creative design. When commercial conductive filaments are 3D printed, the resultant electrodes often possess high contact resistance, and thus post-printing surface modifications are widely used. Deposition of gold nanoparticles (AuNPs) are one of the most widely used electrode modifiers for making electrochemical sensors, however it is not known how the creative design of the electrode surface can influence the electrodeposition of AuNPs and overall electrochemical performance. We explored how the electrodeposition of AuNPs would vary on the surface of electrodes with varying scales and patterns (knurl, revolve and straight). The presence of AuNPs on the electrodes was verified using contact angle and electrochemical impedance spectroscopy. Using scanning electron microscopy, there was a varied distribution of AuNPs on the different scales of surface patterned 3D printed electrodes. This resulted in variations in the current and differences between the anodic and cathodic peak potential (ΔE) for potassium ferrocyanide. The large patterned knurl electrode was effective on monitoring a decrease in nitrite levels with age from feacal pellets. These findings highlight that the scales of surface patterning on a 3D printed electrodes can have a significant influence on the surface modification of the electrode and thus can be used as an effective strategy to enhance electrode performance.