Design and Synthesis of a Dinuclear Copper(II) Probe for Selective Fluorescence Sensing of Pyrophosphate

Abstract

A novel coumarin-based compound DPAC with two dipicolylamine (DPA) arms as the chelator sites was designed and synthesized. The compound DPAC exhibits a highly selective response to Cu2+ ions with a distinctly emission-quenching phenomenon. Moreover, the in situ formed complex DPAC-Cu2+ was used for the detection of pyrophosphate (PPi). The binding manner of probe DPAC-Cu2+ with PPi in 1 : 1 stoichiometry was supported by the Benesi-Hildebrand fitting, ESI-MS and HPLC analysis. The linear range of PPi concentration was 1-4 μM, and the detection limit was 0.53 μM. The competing experiments illustrated that the probe DPAC-Cu2+ had good sensitivity and selectivity for PPi than other anions, including ATP, ADP, AMP, and Pi in CH3CN : HEPES (3 : 2, v/v, pH=7.20) buffer. Further, cell fluorescence imaging experiments indicated that the probe DPAC-Cu2+ had a potential to be used to detect PPi in vivo.

A Coumarin-Based Fluorescence Probe for Selective Recognition of Cu2+ Ions and Live Cell Imaging

“…S1b). The detection limit of L for Cu 2+ ions was estimated about 3 μM based on LOD ðLimit Of DetectionÞ = 3σ/s, where σ and s represent the standard deviation of blank measurements and the slope between concentration of Cu 2+ ions and fluorescence 3 Journal of Sensors intensity, respectively [42]. Thus, the probe L shows excellent sensitivity and low detection limit for the detection of Cu 2+ .…”