Fabrication and characterization of extrinsic electrochemically modified graphite reinforcement carbon paste electrode for selective determination of Cu(II) in trace levels

Abstract

An electrochemical oxidation of copper species has been successfully performed by using electrochemically modified 8‑hydroxy quinoline graphite reinforcement carbon paste electrode; in other words, quinolyl graphite reinforcement Carbon paste electrode (Q/GRCPE). Scanning electron microscopy (SEM) was used for the morphological characterization of the electrode before the modification and after modification and utilization. Under the optimal conditions of cyclic voltammetry (CV) and square wave adsorptive anodic stripping voltammetry (SWAdASV), the electrochemical oxidation of Cu(II) can be investigated. The performance of the electrochemically modified sensor was systematically studied. The experimental data suggested that the electrochemically modified sensor exhibited excellent catalytic activity for the electrochemical oxidation of Cu(II) with a detection limit (LOD) 2.1 × 10−11 M. The application of the electrochemically modified sensor for the detection of Cu(II) in Tap water (TW), ground water (GW) and Nile River water (NRW) showed good recovery with reproducible results. The peak currents of Cu(II) were evaluated within a wide concentration range, in favor of more durability, sensitivity, and selectivity which suitable for investigation of real samples. It was shown that the proposed electrochemically modified Q/GRCPE proved to be a cheap "pre- alarm" tool for rapid determining of Cu(II) in environmental water samples even in the presence of some interfering ions. The adsorptive accumulation of Cu(8-HQ)2, approaches results in an effective preconcentration of Cu(II) with short adsorption time (30 s).