Fitri Dara, Ichan Chandra Dewa, Ali Aulia Ghozali, Cepi Kurniawan, Robeth V. Manurung, Asep Rohiman, Muhamad Nasir
This research focuses on the synthesis and application of the organic Schiff base ligand N,N′-bis(salicylidene)ethylenediamine (salen), synthesized from salicylaldehyde and ethylenediamine, as a key molecular recognition element. The salen structure, featuring characteristic imine (-C=N-) and phenolic hydroxyl (-OH) functionalities as tetradentate N2O2 donor sites, was confirmed using Fourier transform-infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy, establishing its structural integrity for Ni(II) chelation. The synthesized salen was subsequently used to modify a screen-printed carbon electrode (SPCE). Electrochemical impedance spectroscopy (EIS) results revealed that salen modification significantly reduced the charge transfer resistance (R ct) from 1231.6Ω to 296.3Ω, thereby enhancing electron transfer kinetics. Salen-modified SPCE demonstrated excellent analytical performance for Ni(II) detection using differential pulse anodic stripping voltammetry (DPASV), with limit of detection (LoD) was 4.86mM, linear range of 10-100mM (R 2 = 0.9981), sensitivity of 18.13μA/mMcm2, and good selectivity against Fe(II) interfering ions. This study highlights the pivotal role of the salen framework in developing cost-effective and efficient electrochemical sensors for environmental nickel monitoring. © 2026 IUPAC & De Gruyter 2026.
Research Center for Environment and Clean Technologies, National Research and Innovation Agency, B.J. Habibie Science and Technology Area, South Tangerang, 15314, Indonesia; Departement of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang, Sekaran, Gunung Pati, Semarang City, 50229, Indonesia; Research Collaboration Center for Electrochemistry, BRIN-Diponegoro University, Semarang, 50275, Indonesia; Research Center for Electronics, National Research and Innovation Agency, Samaun Samadikun Science and Technology Area, Jl. Sangkuriang, Bandung, 40135, Indonesia; Center of Geological Survey, Geological Agency, Ministry of Energy and Mineral Resources, Jl. Diponegoro No. 57, Bandung, 40144, Indonesia
