Innovative urea sensor: Pt/Graphene/Copper electrode via laser and drop casting techniques

A novel nanostructured electrode has been developed for the sensitive electrochemical determination of urea. Ligand-free platinum nanoparticles averaging 10 nm in size were synthesized via pulsed laser ablation of a Pt target submerged in water (PLAL). These nanoparticles were drop-cast onto single-layer graphene (Gr) supported on a copper substrate, resulting in the Pt/Gr/Cu electrode. The modified electrode was integrated into a three-electrode electrochemical cell for urea determination at low concentrations. Voltametric mode revealed a detection limit of 0.5 mM, with a 0.5–10 mM linearity response region and a 0.1238 mA mM−1 cm−2 sensitivity. Measurements using the impedimetric mode by electrochemical impedance spectroscopy (EIS) further validated these findings, yielding a sensitivity of 0.0217 mM−1 cm−2 within the concentration range of 1–8 mM and confirming the detection limit of 0.5 mM.