Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej Development of selective Co 2+ ionic sensor based on various derivatives of benzenesulfonohydrazide (BSH) compound: An electrochemical approach Mohammad Musarraf Hussain a,b , Abdullah M. Asiri a,b , Muhammad Nadeem Arshad a,b , Mohammed M. Rahman a,b, ⁎ a Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia b Center of Excellence for Advanced Material Research, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia HIGHLIGHTS • Benzenesulfonohydrazide (BSH) was synthesized by condensation method. • BSH/Nafion/GCE assembly made by chemical coating technique. • Highly sensitive Co 2+ ionic sensor by I-V method. • Environmental real pollutants were analyzed. • Green environment. GRAPHICAL ABSTRACT ARTICLE INFO Keywords: Benzenesulfonohydrazide Cobalt ions Sensitivity Glassy carbon electrode Electrochemical method Real sample analyses ABSTRACT Benzenesulfonohydrazide (BSH) derivatives were synthesized using a simple condensation technique from the precursors of benzaldehyde, 2-hydroxy-benzaldehyde, 2-hydroxy-1-naphthaldehyde, benzenesulfonylhydrazine, and 4-methyl-benzenesulfonylhydrazine in a medium to good yield, which had been crystallized in acetone, ethyl-acetate, ethanol, and methanol. BSH compounds were characterized in details by using different spec- troscopic techniques such as 1 H-NMR, 13 C-NMR, FTIR, and UV–Vis. Structures of the BSH molecules were confirmed using a single crystal X-ray diffraction method (SCXRDM) and used for the selective detection of the heavy metal ion (HMI), cobalt (Co 2+ ) using a reliable electrochemical approach. A thin layer of BSH derivatives were made onto a flat glassy carbon electrode (GCE) using a conducting binding agent (Nafion; Nf) in order to fabricate a sensitive and selective Co 2+ sensor probe (BSH/Nf/GCE). Sensitivity, LOD, and LOQ of the modified sensor towards Co 2+ were calculated from the calibration curve (CC) and found as 1582.3 pA μM -1 cm -2 , ≈87.6 pM, and 292.0 mM respectively. The BSH/Nf/GCE sensor was applied for the determination of Co 2+ in spiked and extracted samples such as industrial effluent, red-sea water, well water, tap water, and PVC food packaging packs and found satisfactory and acceptable results. 1. Introduction Existence of an adaptable functional group in organic compounds allocate them in a specific and unique types of organic chemistry having huge number of significant applications in biological, catalysis, en- vironmental, medicinal, and organo-metallic chemistry arena. The https://doi.org/10.1016/j.cej.2018.01.130 Received 31 October 2017; Received in revised form 31 December 2017; Accepted 23 January 2018 ⁎ Corresponding author at: Center of Excellence for Advanced Material Research, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia. E-mail address: mmrahman@kau.edu.sa (M.M. Rahman). Chemical Engineering Journal 339 (2018) 133–143 Available online 31 January 2018 1385-8947/ © 2018 Elsevier B.V. All rights reserved. T