A new 2D Zn(II)-based coordination polymer as highly sensitive selective fluorescent probe for of glutathione

Abstract

Fluorescence-based sensing has emerged as an effective strategy for detecting biomolecules with high sensitivity and selectivity. In this study, a new Zn(II)-based coordination polymer (CP), {Zn(Cl-L)(DPP)]·1.5DMF}_n (1), was synthesized and explored as a fluorescence sensor for the detection of glutathione (GSH). The coordination polymer was synthesized via a solvothermal method, and its structural characterization was confirmed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). CP 1 exhibited strong quenched upon interaction with GSH, indicating a strong binding affinity. Mechanistic investigations, including Inner Filter Effect (IFE) correction and XPS analysis, confirmed that the fluorescence quenching was primarily attributed to IFE and possible electron transfer interactions between 1 and GSH. The quenching constant (K_sv) was determined to be 0.993 × 10⁻³ M⁻¹, and the detection limit (LOD) was calculated as 2.38 × 10⁻⁵ M, highlighting the high sensitivity of the sensor. Additionally, fluorescence lifetime analysis showed a decrease from 41.2 μs to 33.1 μs upon GSH interaction, indicating significant changes in the excited-state molecular environment. The practical applicability of this sensing method was evaluated in real water samples, including deionized (DI) water, tap water, and river water, with excellent recovery rates ranging from 93.04 % to 100.98 % and relative standard deviations (RSD) below 2.2 %, confirming the reliability and accuracy of the method. This study establishes 1 as an effective, selective, and sensitive fluorescence probe for GSH detection, with potential applications in environmental monitoring, biomedical diagnostics, and clinical research.