Endoplasmic reticulum-targeted multifunctional fluorescence probe for the determination of peroxynitrite, viscosity and alcohol content.

A first three-channel fluorescence probe (PVA) was designed and synthesized for the detection of peroxynitrite (ONOO−, 480–500 nm), viscosity (604 nm), and alcohol content (696–722 nm). Notably, the PVA exhibited the ability to co-localize the endoplasmic reticulum (ER), successfully detected the changes in ONOO− in the endoplasmic reticulum (ER) of living cells (RAW 264.7 and HepG2 cells), as well as the fluctuations of ONOO− levels triggered by acetaminophen (APAP). As a sensitive fluorescence probe, PVA was utilized to monitor viscosity changes induced by nystatin and rapamycin. As the viscosity increased, the twisted intramolecular charge transfer (TICT) in PVA was suppressed, resulting in a significant red fluorescence enhancement at 604 nm. Furthermore, PVA successfully tracked the process of endoplasmic reticulum autophagy (ER-phagy) under starvation conditions. Importantly, PVA demonstrated great potential for detecting alcohol content. Therefore, the development of a single fluorescent probe capable of three-channel sensing for ONOO−, viscosity, and ethanol content holds significant potential as a versatile tool in various fields, particularly in biological microenvironments, and industrial applications. PVA provides a conceptual framework for the rational design of future multifunctional probes.