Search

[Display omitted] • A new dye was synthesized and the spectral properties were studied. • The dye showed good spectral properties and was used to detect SO 2 derivatives. • The reactivity of the probe could be regulated by the thiomorpholine group. A new coumarin-hemicyanine dye was synthesized and used as a ratiometric fluorescent probe for SO 2 derivatives (HSO 3 -/SO 3 2-). The probe showed deep-red fluorescence, ratiometric response, good selectivity, low detection limit and well-separated emission bands. Moreover, the probe was mitochondria-targeted, and was applied to image SO 2 derivatives in living cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new pH sensitive fluorescent probe termed NAP-MDA is developed. • NAP-MDA possesses an excellent linear dependence with neutral to alkaline pH. • NAP-MDA is photostable and solely sensitive to pH. • NAP-MDA is successfully utilized to visualize the intracellular pH. A new pH-sensitive fluorescent probe NAP-MDA was designed and synthesized. NAP-MDA consists of 1,8-naphthalimide as fluorophore, morpholine and N,N-dimethylethylenediamine as pH-responsive groups. Due to the photoinduced electron transfer (PET) mechanism, the fluorescence of 1, 8-naphthalimide was thoroughly quenched under alkaline condition (pH > 10.0), however, NAP-MDA displayed increasing fluorescence as the rise of acidity. Notably, NAP-MDA possessed an excellent linear dependence with neutral to alkaline pH (7.2–9.4), with a pKa of 8.38. NAP-MDA had good photostability and reversibility. Meanwhile, the probe was selective to pH without interference from common reactive species, temperature and viscosity. Fluorescent testing strips were fabricated with NAP-MDA and were successfully utilized to visualize the different pH with a handhold UV lamp. Confocal fluorescence imaging in live cells demonstrated that NAP-MDA mainly fluoresced in lysosomes, and could be applied for quantification of the pH within live cells. [ABSTRACT FROM AUTHOR]