Development Of Chemiluminescence Probes For Hydroxyl Radical And Its Application In Biology

Recently, there is currently great interest in researching the importance of oxygen activity and reactive oxygen species radical in biological processes. Therefore, the design of reactive oxygen species probe has become a premise to study the roles of reactive oxygen species in biological processes. So far, the organic fluorescent probes have been commonly designed for the detection of individual ROS. However, their applications are limited by their susceptibility to photobleaching, biotoxicity, and spontaneous autoxidation. Compared with the traditional organic fluorescent probe, the inorganic fluorescent material QDs has excellent optical properties, electrical properties, etc. However, a wide variety of ROS can quench the fluorescence of QDs, impeding the practical applications of QDs as a fluorescence probe for an individual ROS. In addition, the reported CL probes exhibited a low selectivity towards·OH over other reactive oxygen species. Therefore, we hope developing new CL probes with the improved performances for·OH. The properties of nanomaterial probe of the MMT or QDs have been improved through the functionalization processes, such as stability, biocompatibility. We improved the selectivity of the traditional reactive oxygen species probe. The main research contents are as follows:(1) We here report that a novel rhodamine B (RhB)-MMT composite material has been successfully fabricated by attachment of trace RhB on the surface of MMT through electrostatic attraction. Interestingly, the as-prepared RhB-MMT hybrids can facilitate the electrophilic interaction between RhB and·OH, generating an ultrastrong CL emission. The validation of the proposed method is checked by detecting "OH in untreated and gentamicin treated mouse plasma samples.(2) In the present work, citrate can be an excellent candidate as capping ligand to substitute thiol for synthesis of water soluble QDs owing to its low-toxicity and good biocompatibility. On the other hand, citrate can act as an electron donor on the metal surface. The metal-citrate complex on the surface of the CdTe QDs has electron-injection ability into the LUMO of the CdTe QD core. In combination with the hole injection from "OH, the excited-state QDs would be formed, which could emit light when returning to the ground state. Finally, its validation is confirmed by monitoring endogenous release of ·OH in living cells.