A ESIPT turn-on metal-free fluorescent probe for sensing nitroxyl (HNO) was developed.
Large emission spectral shift from weak 404 nm to strong 520 nm in responding to HNO, as a consequence of the ESIPT turn-on.
The probe exhibits a selective response to HNO over other biological reductants in solution.
The probe was applied for quantitative detection of HNO in bovine serum with satisfactory results.