Triazole-tethered naphthalimide-ferrocenyl-chalcone based voltammetric and potentiometric sensors for selective electrochemical quantification of Copper(II) ions

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2022-01, Vol.905, p.115966, Article 115966
• Main Authors: Kaur, Sarbjeet, Shalini, Ahmad Shiekh, Bilal, Kumar, Vipan, Kaur, Inderpreet
• Format: Article
• Language: English
• Subjects: Carbon paste electrode; Chemical sensors; Copper; Cu2+ sensor; Cyclic voltammetry; Differential pulse voltammetry; Electrochemical analysis; Ferrocene; Gibbs free energy; Mass spectrometry; NMR; Nuclear magnetic resonance; Sensors; Triazoles; Voltammetry
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2021.115966

[Display omitted] •A ferrocene based TNFC was synthesized and found sensitive towards Cu2+.•UV, fluorescence, DFT, NMR and HRMS studies confirmed binding of TNFC with Cu2+.•TNFC exhibited voltammetric response towards Cu2+ with LOD 0.09 µM.•TNFC-CPE showed a Nernstian slope of 30.0 mV/decade with LOD 0.79 µM.•TNFC-CPE was successfully applied for estimation of Cu2+ in water and milk products. A triazole-tethered naphthalimide-ferrocenyl-chalcone (TNFC) derivative was synthesized and investigated for its electrochemical behavior with subsequent successful application as a receptor for the development of differential pulse voltammetric (DPV) and potentiometric sensors for quantification of Cu2+ after receiving confirmatory evidences from UV–Vis, Fluorescence and DFT studies. Cyclic voltammogram of TNFC exhibited two redox peaks at +0.51 V and +0.59 V corresponding to ferrocene/ferrocenium ion redox couple in the potential range of 0–1.0 V vs Ag/Ag+. On addition of Cu2+, Cyclic voltammogram of TNFC shifted toward more positive potential (anodic shift), indicating the formation of TNFC-Cu2+ complex. DPV sensor demonstrated a selective response towards Cu2+ in the concentration range of 0–26 µM with detection limit of 0.09 µM. The TNFC modified carbon paste electrode (CPE) exhibited a selective response for Cu2+ with Nernstian slope of 30.0 mV/decade in the concentration range of 1.0 × 10−6−1.0 × 10−1 M and detection limit 0.79 µM. High binding constant (3.2 × 104 M−1) and negative value of Gibbs free energy (−25.69 kJmol−1) calculated using Benesi-Hildebrand (BH) equation confirmed the favorable complexation between TNFC and Cu2+ which was also validated using 1H NMR and mass spectrometry. The proposed TNFC-CPE was successfully utilized for quantification of Cu2+ content in real samples of water and milk products.