A novel functional fluorescent probe based on a pyrene derivative for the detection of multiple pollutants

In regards to environmental protection, the detection of metal ions and pesticide residues remains meaningful and challenging. Herein, we report a novel multifunctional fluorescent probe based on a pyrene derivative, 4-[(pyren-1-ylimino)methyl]benzene-1,3-diol (PBD), that can recognize Al3+, Cr3+, Fe3+ and mesotrione with quantification of the sample being tested. In addition, the PBD probe can detect Hg2+ in a “turn-off” fluorescent mode. It is worth noting that the hydrolysis of carbon–nitrogen double bonds in the PBD Schiff base structure is targeted and catalyzed by Fe3+, Al3+ and Cr3+ cations, while mesotrione can also promote the hydrolysis of Schiff bases through the formation of intermolecular hydrogen bonds. Consequently, the PBD probe with weak fluorescence was converted to 1-aminopyrene in a localized state, showing stronger fluorescence. In addition, chelation may lead to fluorescence quenching of the PBD probe in the presence of Hg2+. The quantitative determination of Fe3+, Al3+, Cr3+ and mesotrione is achieved in which the limit of detection (LOD) is calculated to be 0.52, 0.30, 0.32 and 0.70 μM, respectively. Hg2+ detection is realized with an LOD of 1.93 μM. Moreover, the sensitive PBD probe is utilized to determine the amount mesotrione in actual water samples, demonstrating its potential practical applications. In addition, the multifunctional PBD probe can be employed for intracellular imaging of Fe3+ and Hg2+ based on its low cytotoxicity and certain water solubility. The present work describes a very competitive fluorescent probe for the detection of different types of pollutants, which is relevant to future research regarding environmental contaminant monitoring.