TDDFT study on the simultaneous sensing mechanism for peroxynitrite and glutathione by a bifunctional fluorescent probe

Wang Si-Jia; Li Peng-Yuan; Zhang Hang; Shi Lei; Liu Dong; Li Guang-Yue

doi:10.1016/j.saa.2022.122314

TDDFT study on the simultaneous sensing mechanism for peroxynitrite and glutathione by a bifunctional fluorescent probe

Spectrochim Acta A Mol Biomol Spectrosc. 2023 Apr 15:291:122314. doi: 10.1016/j.saa.2022.122314. Epub 2023 Jan 4.

Authors

Wang Si-Jia¹, Li Peng-Yuan¹, Zhang Hang², Shi Lei¹, Liu Dong³, Li Guang-Yue⁴

Affiliations

¹ College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China.
² Modern Technology and Education Centre, North China University of Science and Technology, Tangshan 063210, PR China.
³ College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China. Electronic address: liudong@ncst.edu.cn.
⁴ College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China. Electronic address: gyli@ncst.edu.cn.

PMID: 36621031
DOI: 10.1016/j.saa.2022.122314

Abstract

Using time-dependent density functional theory (TDDFT) method, the response mechanism of a reported bifunctional fluorescent probe for simultaneous recognition of peroxynitrite and glutathione (Chem. Commun. 2018, 54, 11336) was theoretically studied. Calculated vertical excitation energies based on the ground-state and excited-state geometries were consistent with the corresponding experimental ultraviolet-visible and fluorescence spectra. In the ground state, electron delocalization in the probe was limited because its geometry was restrained by steric hindrance. Frontier molecular orbital analysis has shown that the probe should undergo photoinduced electron transfer (PET) from the benzothiazole moiety to the maleimide moiety after excitation. The nonplanar structure together with PET led to fluorescence quenching of the probe. The probe could be dealkylated by peroxynitrite anion. The resulting intramolecular hydrogen bond increasesd the planarity of the molecule, while also gave rise to an excited-state proton-transfer process. Moreover, the addition reaction between the probe and glutathione inhibited the PET process. These two analytes together contributed to the fluorescence enhancement of the final product. This theoretical sensing mechanism for peroxynitrite and glutathione may potentially be important for the design and enhancement of novel probes.

Keywords: ESPT; Fluorescent probe; PET; Sensing mechanism; TDDFT.