Investigating electrochemical sensing properties of PIGE/rGO/Cu@nHAp for dynamic detection of urea

Reduced graphene oxide/Copper nanohydroxyapatite particles (rGO/Cu@nHAp) were deposited on a paraffin-impregnated graphite electrode (PIGE) surface and used as a non-enzymatic sensor for Urea. nHAp has good ion exchange properties and increased conductivity when soaked in copper. The electrode is prepared by a simple 2-step process including first the electrochemical reduction of Graphene Oxide (GO), followed by drop casting of Cu@nHAp. The modified electrode was thoroughly characterized using FTIR, ATR-IR, Raman, XRD, SEM, and TEM, which supported the presence of rGO/Cu@nHAp over PIGE. The response of the PIGE/rGO/Cu@nHAp in various electrolytes were studied. The PIGE/rGO/Cu@nHAp showed good electrochemical activity towards Urea in NaNO₃ as a supporting electrolyte. The sensing properties of the modified electrode towards urea were studied using Cyclic Voltammetry and Square Wave Voltammetry. The observed electrocatalytic current is having two dynamic linear ranges of 1 – 2 fM and 0.5—6.5 mM with a limit of detection of 0.34 fM. The interference of other related analytes was also studied under optimized conditions. The stability and reproducibility performance of the modified electrode was found to be very satisfactory.