Syntheses And Bioassay Applications Of Novel Ruthenium(?) Complex-Based Phosphorescence Probes

Ruthenium(?)complexes have some advantages,such as large Stokes shift,visible-light excitation,resistant to the photobleaching,and good biocompatibility,which enable them to be suited for the development of luminescence probes to reveal the function of physiologically active components in vivo and in vitro.In addition,Ru(?)complexes usually have long luminescence lifetimes,which allow them to be used for time-gated luminescence detection to extend their feasibility in bioassays.In this dissertation,four novel Ru(?)complex-based phosphorescence probes for specific detection of bioactive components were successfully designed and synthesized,and their applications to bioassays were investigated.A novel "dual-key-and-lock" strategy-based Ru(?)complex probe,Ru-FA,was constructed for specific recognition of formaldehyde.Due to the presence of strong intramolecular photoinduced electron transfer(PET),the phosphorescence signal of the probe is very weak.The specific reaction between Ru-FA and formaldehyde can only occur in the acidic condition,which makes the probe be used for accurate phosphorescent imaging of formaldehyde in cell lysosomes.Benefiting from the long-lived emissions of Ru(?)complexes,Ru-FA is favorable to be used for detecting formaldehyde in autofluorescence-rich biological samples.In addition,using Ru-FA as a probe,visualization of tumor-derived endogenous formaldehyde was demonstrated,which provides an effective method for early clinical diagnosis and visualized treatment of tumors.A ruthenium(?)complex probe,Ru-GST,was designed and synthesized for the specific recognition of glutathione S-transferases(GSTs)in the presence of glutathione(GSH).The phosphorescence of the probe is weak due to the strong intramolecular PET.After response to GSTs,Ru-SR with strong phosphorescence is generated.Based on the excellent performance of the probe in quantitative time-gated luminescence detection and phosphorescent imaging analysis of GSTs in biological samples,the probe was successfully used for monitoring the changes of GSTs content in livers and sera of mice during the process of drug-induced acute liver injury.This study provides not only a useful method for the quantitative time-gated luminescence detection and in situ real-time analysis of GSTs in biological samples,but also a valuable reference for the clinical diagnosis of drug-induced liver injury.A novel Ru(?)complex luminescence probe that can be used for biothiols detection and discrimination,Ru-NBD,was designed and synthesized.Ru-NBD is nonluminescent due to the quenching of Ru(?)complex emission by PET from Ru(?)center to NBD and the quenching of NBD emission through 4-substitution with "O" ether bond.Ru-NBD is capable of reacting with GSH to form long-lived red-emitting Ru-OH and nonemissive NBD-SR1,while reacting with cysteine(Cys)/Homocysteine(Hcy)produce Ru-OH and short-lived green-emitting NBD-NR.The long lifetime emission of Ru(?)complex allows elimination of short lifetime NBD-NR fluorescence for total biothiols detection by time-gated luminescence analysis,and the remarkable difference in luminescence color response allows discrimination of GSH and Cys/Hcy through steady-state luminescence analysis.The success of this probe provides a useful approach for biothiols detection and discrimination,and also a valuable strategy for the design of the probes that can be used for multicomponents discrimination.A novel Ru(?)complex probe,Ru-PNBD,was designed and synthesized for colorimetric and luminescent detection of H2S.In terms of phosphorescent recognition,the emission of Ru-PNBD was quenched as a result of the PET process from Ru(?)complex luminophore to NBD moiety.Upon response to H2S,the specific SNAr substitution reaction occurred to cleave the NBD moiety from Ru-PNBD to form emissive Ru-PH.In terms of colorimetric recognition,the aqueous solution of Ru-PNBD is light yellow.After reacting with H2S,in addition to light yellow of Ru-PH,red NBD-SH is also formed.Ru-PNBD showed good selectivity and high sensitivity in the detection of H2S,which facilitated it to be used as a probe for the detection of H2S in real water samples,living cells,Daphnia magna,and zebrafish.