An electrochemical sensor–adsorbent for lead (Pb2+) ions in an aqueous environment based on Katiragum–Arginine Schiff base

Abstract

Herein we report a highly sensitive and selective electrochemical sensor–adsorbent for the simultaneous detection and removal of highly toxic lead (Pb²⁺) ions from an aqueous solution by a Katiragum–Arginine Schiff base. The sensor is developed by the periodate oxidation of Katiragum and modified to a Schiff base by reaction with an amino acid, L-arginine (KGDR). The KGDR is characterized by NMR, FTIR, FESEM analysis and HRMS spectra. The Katiragum–Arginine Schiff base material is used as a sensor–adsorbent for Pb²⁺ from aqueous solution. Sensing of Pb²⁺ is analyzed by the electrochemical method with a detection limit of 0.146 μM with respect to the concentration of Pb²⁺. The Schiff base/glassy carbon electrode (KGDR/GCE) is highly selective towards Pb²⁺ ions in comparison to other environmentally relevant ions as well as in water samples. KGDR shows a remarkably high adsorption capacity towards Pb²⁺ ions with maximum specific removal (q_m) of 5482.46 mg g⁻¹. Various isotherm and kinetic models are used to analyze the data and the Langmuir and pseudo-second order kinetic model are followed for Pb²⁺ adsorption.