A Multifunctional and Fast-Response Lysosome-Targetable Fluorescent Probe for Monitoring pH and Isoxaflutole

Abstract

A new chemosensor, namely N-(2-morpholinoethyl)acetamide-4-morpholine-1,8-naphthimide (MMN), was designed and synthesized through an amidation reaction. MMN was fabricated as a multifunctional fluorescent probe for monitoring pH and isoxaflutole. MMN exhibited excellent stability in MeCN/H2O (v/v, 9/1), with an obvious “off–on” fluorescence response toward pH changes due to intramolecular charge transfer (ICT), where the linear response ranges of MMN in the weakly acidic system were from 4.2 to 5.0 and from 5.0 to 6.0 with apparent pKa = 4.62 ± 0.02 and 5.43 ± 0.02. Based on morpholine as the lysosome targetable unit, MMN could selectively locate lysosomes in live cells. MMN also successfully detected the presence of H+ in test papers. Finally, MMN could specifically recognize isoxaflutole at a detection limit of 0.88 μM. A possible sensing mechanism was identified based on density function theory calculations. These results indicate that MMN could be a superior potential chemosensor for detecting pH and isoxaflutole selectively and sensitively and could be used in real sample detection.

Supramolecular Dimer as High-Performance pH Probe: Study on the Fluorescence Properties of Halogenated Ligands in Rigid Schiff Base Complex

“…pH plays a significant role in biological and physiological processes as it influences the function of enzymes and other biomolecules that are vital for various cellular activities such as energy generation, DNA replication, and signaling cascades [1][2][3][4]. Minor fluctuations in the pH environment can impact the function of intracellular enzymes and other biomolecules, altering metabolic reactions and other critical cellular processes [5,6].…”

Versatile Dicyanomethylene-Based Fluorescent Probes for the Detection of β-Amyloid in Alzheimer’s Disease: A Theoretical Perspective

“…A variety of detection methods have been reported for the analysis of active substance amyloid related to AD [ 7 , 8 , 9 , 10 ]. Among them, fluorescence microscopy with advantages, such as a simple operation and a high temporal and spatial resolution, is widely used in biomedicine, biodetection, and other fields [ 11 , 12 ]. In this context, a number of fluorescent probes based on organic small molecules for sensing Aβ are developed in consideration of their low cost and facile synthesis [ 13 , 14 , 15 ].…”