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

A dual-channel chemosensor based on rhodamine and BODIPY conjugated dyad for ratiometric detection of Hg²⁺ and fluorescence on–off recognition of Cu²⁺ in aqueous solution and living cells

Li Ma, Gongnv Xu, Xuankai Deng, Dan Wen, and Yanhua Yu

Key Laboratory of Optoelectronic Chemical Materials and Devices, Institute for Interdisciplinary Research, Jianghan University, Wuhan, China

E-mail: wendan701@163.com

Received: 12 July 2022  Accepted: 18 September 2022

Abstract:

A novel probe RB for discriminative detection of Hg²⁺ and Cu²⁺ constructed by rhodamine and BODIPY was designed and synthesized. Probe RB consists of three parts: BODIPY as the energy donor, rhodamine as the energy receptor, and thiosemicarbazide as the reacting site. Probe RB selectively binds with Hg²⁺ and Cu²⁺ ions in in EtOH/H₂O (V/V = 1:1) among tested metal ions. Probe RB exhibited a fluorescence red shift from 513 to 593 nm for Hg²⁺ and a fluorescence quenching for Cu²⁺. The mechanism study showed that the fluorescence changes of probe RB after the addition of Hg²⁺ was due to oxadiazole formation when the thiosemicarbazide moiety was liberated by Hg²⁺-facilitated ring opening of the spirocyclic group, while Cu²⁺ not only opened the spirolactam ring, but also bonded to the opening product through 1:2 mode. It is worth noting that all these types of probes could only detect Hg²⁺ or Cu²⁺ through metal ions-facilitated ring opening of the spirocyclic group mechanism. To the best of our knowledge, probe RB was firstly reported to detect Hg²⁺ and Cu²⁺ discriminatively. Moreover, probe RB demonstrated excellent sensitivity toward Hg²⁺ (LOD 8.36 nM) and Cu²⁺ (LOD 0.16 μM), fast responsive time (within 30 s) and wide pH range (6.0–10.0 for Hg²⁺, 6.0–11 for Cu²⁺). This probe was further successfully applied to Hela cells and could easily discriminate Hg²⁺ and Cu²⁺ through double-channel imaging.

Keywords: Rhodamine; BODIPY; Hg2+ and Cu2+ discriminative detection; Cell imaging

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02504-6

Chemical Papers 77 (1) 583–593 (2023)