Comparison of rhodamine 6G, rhodamine B and rhodamine 101 spirolactam based fluorescent probes: A case of pH detection

Fei Deng; Dongsheng Sun; Shixu Yang; Wei Huang; Chunfang Huang; Zhaochao Xu; Limin Liu

doi:10.1016/j.saa.2021.120662

Comparison of rhodamine 6G, rhodamine B and rhodamine 101 spirolactam based fluorescent probes: A case of pH detection

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Mar 5:268:120662. doi: 10.1016/j.saa.2021.120662. Epub 2021 Nov 26.

Authors

Fei Deng¹, Dongsheng Sun², Shixu Yang³, Wei Huang³, Chunfang Huang³, Zhaochao Xu⁴, Limin Liu⁵

Affiliations

¹ School of Chemistry and Chemical Engineering, Jinggangshan University, Ji'an, Jiangxi 343009, China. Electronic address: dengfei@jgsu.edu.cn.
² School of Medicine, Taizhou University, Taizhou, Zhejiang 318000, China.
³ School of Chemistry and Chemical Engineering, Jinggangshan University, Ji'an, Jiangxi 343009, China.
⁴ CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Electronic address: zcxu@dicp.ac.cn.
⁵ School of Chemistry and Chemical Engineering, Jinggangshan University, Ji'an, Jiangxi 343009, China. Electronic address: llm24@126.com.

PMID: 34865976
DOI: 10.1016/j.saa.2021.120662

Abstract

Ring-opening reaction of rhodamine spirolactam has been widely applied to construct fluorescent probes. The fluorescence properties of the probe were finely tuned for specific purpose through changing the rhodamine fluorophore. However, the influence on response range and kinetic parameters of the probe during the change has been seldom discussed. Herein, we took pH detection as an example and constructed spirolactam based probes (RLH A-C) with Rhodamine 6G, Rhodamine B and Rhodamine 101. The pK_a values and observed rate constant k_obs of RLH A-C were determined and found to negatively correlated with the calculated Gibbs free energy differences ΔG_C-O and ΔG_TS respectively. The potential applications of RLH A-C in imaging acidic microenvironment were also investigated in cells. We expect the comparison of rhodamine fluorophores will facilitate the quantitative optimization of rhodamine spirolactam based fluorescent probes.

Keywords: Fluorescent probe; Rhodamine; Spirolactam; pH.

MeSH terms

Fluorescent Dyes*
Hydrogen-Ion Concentration
Rhodamines

Substances

Fluorescent Dyes
Rhodamines
rhodamine 6G
rhodamine B