ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

An optical chemosensor for nano-level determination of Pb²⁺ and Cu²⁺ in aqueous media and its application in cell imaging

Nasibeh Azizi Khereshki, Asadollah Mohammadi, Hassan Zavvar Mousavi, Nina Alizadeh, and Mehdi Evazalipour

Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran

E-mail: a_mohammadi@guilan.ac.ir

Received: 12 November 2022  Accepted: 4 March 2023

Abstract:

In this work, a colorimetric chemosensor containing thiazolidinedione as a biologically active molecule (NTCS) was successfully used for the highly selective and ultra-sensitive detection of Pb²⁺ and Cu²⁺ ions in different water samples as well as in a living cell both visually and optically. The characterization of the probe was confirmed by NMR, FT-IR spectroscopy, and UV–Visible absorption techniques prior to experiments. Probe NTCS exhibits an obvious color change because of a ligand to metal charge transfer (LMCT) complex that transforms it from colorless to yellow in the presence of Cu²⁺ and from colorless to peach in complexation with Pb²⁺ in aqueous methanol–water solutions that could make it a suitable ‘naked-eye’ indicator for Cu²⁺ and Pb²⁺. Based on Job’s plot analysis, the interaction binding mode of probe NTCS with Cu²⁺ (NTCS-Cu²⁺) and Pb²⁺ (NTCS-Ni²⁺) was found to be 1:1 stoichiometry complex. The stability of probe-ligand in different pH ranges (9–11) was concerned with determination of the optimum pH for the detection of Cu²⁺, and Pb²⁺ ions, which provides NTCS chemosensor suitable for quantitative analysis of the above-mentioned ions under physiological state. The results illustrated that the low detection limits (LOD) for Cu²⁺ and Pb²⁺ were calculated as 27.7 nM and 0.79 nM, respectively. In order to quick and convenient “naked-eye” detection of the Cu²⁺ and Pb²⁺ ions in pure aqueous media, low-cost NTCS-based test paper strips were successfully handed-down. MTT assay and bioimaging results indicated the probe has low toxicity, biocompatibility, and successful cellular absorption; hence, the probe can be used in Cu²⁺ and Pb²⁺ recognition in living cells with high selectivity and sensitivity compared to other chemosensors being researched in recent years.

Graphical abstract

Keywords: Colorimetric chemosensor; Thiazolidinone; 2-Hydroxy-1-naphthaldehyde; Cu2+ and Pb2+ ions; Cell imaging

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02770-y

Chemical Papers 77 (8) 4201–4215 (2023)