Selective anions mediated fluorescence turn-on, aggregation induced emission (AIE) and lysozyme targeting properties of pyrene-naphthalene sulphonyl conjugate

We have designed and synthesized a novel pyrene-naphthalene sulphonyl conjugate, 1-((1Z)-(4-((Z)-4-(pyrene-1-yl)methyleneamino)phenylsulfonyl)phenylimino)methyl)naphthalene-2-ol (PSN) through a facile two-step reactions. It was characterized by various spectral techniques. Fluorescence spectral studies showed that compound PSN featured fluorescence enhancement upon increasing the water content in THF. This can be attributed to the phenomena of aggregated induced emission (AIE), which is confirmed by SEM and AFM studies, due to the restriction of -CH=N isomerization of PSN. The anion sensing of PSN was examined with various anions. Among these anions, H2PO4- and F- ions were selectively sensing with a low detection limit of 3.52 x 10(-7) M and 7.23 x 10(-7) M, respectively, and an obvious color change from yellow to orange was observed by the naked eye. The mechanism of sensing involved the formation of hydrogen bonding interaction between O-H group of PSN and H2PO4-/F- ions. The binding of PSN with LYZ was also examined by docking studies, which shows that H-bonding and hydrophobic interactions play crucial roles for the interaction of LYZ toward PSN. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel pyrene-naphthalene sulphonyl conjugate, PSN, was designed and synthesized and showed fluorescence enhancement in THF with increased water content, attributed to the phenomenon of aggregated induced emission. PSN exhibited selective sensing of H2PO4- and F- ions with low detection limits and a visible color change observed by the naked eye. Docking studies revealed important interactions for the binding of PSN with LYZ, involving hydrogen bonding and hydrophobic interactions.