Tao Ma,Yiyun Li,Changchun Yuan,Zhichun Li,Wenbing Ma,Ling Ma
As a vital biological molecule, H2O2(Hydrogen Peroxide) is involved in different physiological and pathological processes. And in addition to this, H2O2 is suitable for medical wound disinfection, environmental disinfection and food disinfection. Accordingly, it is of high significance to conveniently and effectively detect H2O2 in the environment and organisms. This subject synthesised a fluorescent probe Pyrimidine-Se by using selenomorpholine and pyrimidine dye, which detect H2O2 in an aqueous environment. Pyrimidine-Se has a large Stokes shift (Δλ = 155 nm), which can specifically and quickly quantitatively detect H2O2. When the probe Pyrimidine-Se reacted with H2O2, the Se(II) in the selenomorpholine was oxidised to Se(IV), so the electron withdrawing ability of the electron withdrawing group of Pyrimidine-Se was improved, and the fluorescence intensity of the probe were enhanced. Interestingly, Se(IV) can be reduced by GSH (Glutathione) to Se(II) to quench the fluorescence, and this redox cycle can continue several times, which indicated that it can have a potential of real-time monitoring the redox state in vivo. The probe was also satisfactorily used to detect H2O2 in Argentina Bloodfin larvaes and abnormal H2O2 content in some organs was detected.
A simple selenamorpholine-based fluorescent probe has been designed and synthesized using a combination of selenamorpholine and a BODIPY fluorophore. BODIPY–Se has a low pKa value of 4.78 because of the selenamorpholine unit, which is beneficial for the probe to detect the lysosome. BODIPY–Se can turn on partial fluorescence only in lysosomes, due to a PET-inhibited process of protonation of selenamorpholine. In addition, the selenamorpholine unit of BODIPY–Se could selectively react with H2O2 through a redox reaction, leading to the alteration of the valence state of selenium from Se(II) to Se(IV) and an additional PET-inhibited process. When BODIPY–Se tracked H2O2 in lysosomes, the two PET-inhibited processes would obviously amplify the fluorescence signal in living cells and in vivo. The probe could also detect the redox cycles between H2O2 and GSH continuously. Using confocal fluorescence imaging, the fluorescence localization of lysosomes demonstrated that BODIPY–Se could successfully target lysosomes. The probe could not only detect exogenous/endogenous H2O2 in living cells, but could also realize real-time monitoring of H2O2 in cancer cells and zebrafish. The results proved that BODIPY–Se is a promising fluorescent probe in biological applications.
Redox homeostasis is the guarantee for the normal operation of living organisms. Given its importance, monitoring dynamic changes of redox state will facilitate the study of relevant physiological and pathological processes. Herein, a two-photon fluorescent probe NA-Se with selenomorpholine as the response site has been developed for reversible detection of redox state. NA-Se exhibits outstanding analytical performance, including a rapid response to ClO − within 8 s, a detection limit as low as 13.3 nM, and at least 10 redox reversible cycles. Furthermore, NA-Se has improved water solubility and extremely low cytotoxicity, making it ideal for bioimaging. Finally, NA-Se has been successfully applied to monitor the ClO − /GSH redox cycle in living cells and zebrafish. This work may provide an effective tool for studying redox state and related diseases in vivo.