A dual-response triphenylamine-based fluorescent probe for selective sensing of copper(II) and nitric oxide in live cells

The development of bifunctional fluorescent probes for rapid and sensitive detection of copper(II) and nitric oxide (NO) in vivo is of significant importance to better understand their roles in human health. In this paper, a novel dual-response triphenylamine-based fluorescent probe, BQ, was developed for the detection of Cu2+ and NO in live cells. The sensing mechanism of the probe towards Cu(2+ )can be attributed to the photoinduced electron transfer (PET) process of BQ-Cu2+, resulting in the remarkable quenching of the fluorescence emission. Meanwhile, the addition of NO can make the fluorescent wavelength of the probe red shift due to the intramolecular charge transfer (ICT) effect of BQ-NO, and the sensing mechanisms of BQ towards Cu2+ and NO have been further confirmed by H-1 NMR and the high resolution mass spectrometry (HR-MS) analysis and the density functional theory (DFT) theoretical computation. Furthermore, BQ has the obvious advantages of high sensitivity, rapid fluorescent response, and reliability at physiological pH towards Cu2+ and NO. It is noteworthy that BQ can be used as a sensor for the detection of Cu2+ and NO in live RAW 264.7 cells by fluorescence imaging. (C) 2022 Elsevier B.V. All rights reserved.