Equivalent visualizing biothiols level in synergistically induced ferroptosis using a dual mechanism hybrid probe with excitation-independent sensing property

Ferroptosis, an iron-dependent programmed cell death, is driven by abnormal iron metabolism, free radicals generation, and LPO accumulation. Being the key role in redox homeostasis, GSH concentration has become an important marker in ferroptosis. Meanwhile, the biosynthesis and metabolism of the three biothiols, Cys, Hcy, and GSH, during ferroptosis process may be synchronous inhibition. Thus, revealing the effect of diverse inducers on total biothiols level in ferroptosis is of remarkable significance. To fully utilize the advantages of diversity in construction of intramolecular charge transfer (ICT) probes, and low SBR of photo-induced electron transfer (PET) mechanism, in this work, dual-mechanism strategy by integrating PET mechanism into ICT probes was innovatively proposed. As a proof of concept, a hybrid probe, called NBSD-THD, was designed for biothiols sensing with stable fluorescence turn-on ratios up to 123-fold under excitation range of 640–720 nm. Meanwhile, NBSD-THD was successfully used for quantitative detection of Cys, Hcy, and GSH under three selected excitations (640, 680, and 720 nm), with consistent linear range of 0–20 μM and satisfied detection limit of about 0.2 μM. Given these superiority, NBSD-THD was employed for imaging biothiols fluctuation during ferroptosis synergistic activated by different types of inducers, to prove their function differences on thiols down-regulation. In a word, this delicate design could achieve consistent sensing performance under full-wavelength excitation, providing generality and universality for constructing PET hybrid ICT probe.