Analytical and Bioanalytical Electrochemistry is an international scientific journal published online by the Center of Excellence in Electrochemistry at the University of Tehran, Tehran, Iran. The journal was published quarterly from 2009 to 2011, bimonthly from 2011 to 2018, and has been published in at least eight issues per year since 2018. Analytical and Bioanalytical Electrochemistry - 17 7 2025 09 30 Simultaneous Electrochemical Detection of Copper and Chromium in Drinking Water using 3-Pyrazolyl-pyran-2-one Modified Carbon Paste Electrode 621 634 729839 10.22034/abec.2025.729839 EN Sofia Kerouad Laboratory of Engineering and Applied Technologies, School of Technology, Beni Mellal, Morocco 0009-0006-7993-0236 Madani Ouhaddou Molecular Chemistry, Materials and Catalysis Laboratory, Faculty of Sciences and Technologies, Sultan Moulay Slimane University, BP 523, Beni-Mellal 23000, Morocco Issam Forsal Laboratory of Engineering and Applied Technologies, School of Technology, Beni Mellal, Morocco 0000-0003-2769-8499 Meriem Kasbaji Materials Science, Energy and Nanoengineering (MSN) Department, Mohammed VI Polytechnic University, Lot 660 – Hay Moulay Rachid, 43150, Ben Guerir, Morocco Mohamed Mbarki Engineering in Chemistry and Physics of Matter Laboratory, Faculty of Science and Technologies, Sultan Moulay Slimane University, PB: 523, Beni Mellal, Morocco 0000-0002-7503-4593 Abderrafia Hafid Molecular Chemistry, Materials and Catalysis Laboratory, Faculty of Sciences and Technologies, Sultan Moulay Slimane University, BP 523, Beni-Mellal 23000, Morocco Journal Article 2025 06 05 The contamination of drinking water with heavy metals such as copper (Cu²⁺) and chromium (Cr³⁺) poses significant health and environmental risks, necessitating the development of sensitive and selective detection methods. In this study, a carbon paste electrode (CPE) modified with 3-pyrazolyl-pyran-2-one, a heterocyclic ligand containing nitrogen and oxygen donor atoms, was developed for the simultaneous electrochemical detection of Cu²⁺ and Cr³⁺ ions in drinking water. The interaction between the ligand and metal ions was characterized by Fourier-transform infrared (FTIR) spectroscopy, providing valuable insights into the surface modifications and coordination mechanisms. Electrochemical performance was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV), revealing significant improvements in charge transfer efficiency and electrocatalytic response compared to the unmodified electrode. The sensor demonstrated high sensitivity, low detection limits, and excellent selectivity for Cu²⁺ and Cr³⁺ ions, with recovery rates ranging from 95–106% for Cu²⁺ and 92–105% for Cr³⁺, confirming its accuracy and potential for practical applications in water quality monitoring. These results highlight that surface modification with 3-pyrazolyl-pyran-2-one substantially enhances interfacial electron transfer, providing a promising and reliable platform for the detection of heavy metal ions in aqueous environments. https://www.abechem.com/article_729839_4c886e4a01669c3622b41ce9673a487d.pdf