Design Of Organelle-Targetable Two-Photon Probes For Polarity

Naphthalimide derivatives are widely used flurohpores with the plenty of advantages, such as simple structure, readily modifiable, good photo stability, high fluorescence quantum yield, environment sensitive, higher two-photon absorption cross sections and etc. These derivatives are mainly used in field of fluorescent detection. Currently, it becomes increasingly popular in probes with both detection ability and organelle-targetable. In this paper, Naphthalimide derivatives have been designed to detect microenvironment changes in lysosomes and mitochondria by introducing different group to Naphthalimide. By using these probes, we succeed in monitoring morphological feature of lysosomes and mitochondria during physiological process.MITHPN, a probe for morphological feature of lysosomes membrane is designed and synthesized. Fundamental photophysical properties are first studied including absorbance and fluorescence spectrum, fluorescence quantum yield, and two-photon absorption section in different solvents. The data exhibits its sensitive to the polarity of solvents. Colocalization imaging proves its lysosome targeting ability. Further experiments by employing medicine stimulate and PS particles phagocytose are conducted to monitor morphological feature changes of lysosomes. We also prove that the polarity of normal lysosomes is39.02-38.85Kcal· mol-1by fluorescence lifetime imaging, and this value decreases under medicine stimulating. Moreover, two-photon fluorescence images are collected to demonstrate the advantage of using MITHPN as lysosomal probe for2PFM imaging.PAHPN, a probe for morphological feature of mitochondria membrane is designed and synthesized. Fundamental photophysical properties are also studied including absorbance and fluorescence spectrum, fluorescence quantum yield, fluorescence lifetime and two-photon absorption section in different solvents. The data exhibits its sensitive to the polarity of solvents. Colocalization imaging illustrates its mitochondria targeting ability. Morphological feature changes are monitored under CCCP (carbonyl cyanide3-chlorophenylhydrazone) stimulating and hunger induced apoptosis. Fluorescence lifetime imaging demonstrates that polarity of normal mitochondria is about40.12Kcal· mol-1, and this value decrease and then increases under medicine stimulating. Two-photon fluorescence imaging also prove that PAHPN is a potential two-photon mitochondria probes.