Construction And Application Of Fluorescent Biosensors For Detecting Peroxynitrite

Reactive oxygen species(ROS),which composed of oxygen are widely present in organisms and nature and possessed high oxidation activity.After entering the human body,ROS will produce aging substances which would damage the genetic factors.They have been seen as the biggest culprit of disease and aging.With strong reactivity,they and can react with most biomolecules.Their qualitative and quantitative detection has become an important topic in the field of life sciences and attracted more and more attentions of researchers.The detection of peroxynitroso(ONOO~-),as a kind of ROS with high activity and short life,is particularly important.At present,fluorescent biosensors are widely used to detect various anions and cations,small biological molecules,gas molecules,humidity,temperature and pressure.For their advantages of simple operation,good selectivity,high sensitivity,fast response,and real-time monitoring,fluorescent biosensors have played an important role in life sciences,medical diagnosis,immune analysis,biochemical sensing,bioimaging,food chemistry,materials science,environmental testing and other fields.In this paper,a series of fluorescent biosensors are designed for the endogenous detection of ONOO~-and simultaneous detection of ONOO~-and GSH.The full text is mainly divided into six parts:Chapter 1.This part mainly summarized the structure and properties of ONOO~-in biological systems,and analyzed the pathological damage process that ONOO~-participated in.Discussed various methods that can be used to detect ONOO~-and the research progress in fluorescence sensors.The importance of simultaneous detection of ONOO~-and GSH were also discussed.The four works in this paper were also briefly introduced.Chapter 2.Based on the time-resolved technology,we designed a ratiometric nanoprobe TD-DC for the detection of ONOO~-.Two parameters of luminescence intensity and luminescence lifetime can be used as the detection indicators for detecting.It can be successfully applied to the endogenous ONOO~-test at the subcellular level.What we are proud of is that TD-DC is the first fluorescent probe applying time-resolved technology to the process of detecting ONOO~-successfully.Chapter 3.Based on the nitro,chlorine,amino,hydroxyl and piperazinyl groups that with different push-pull electronic effects,five near-infrared fluorescent probes1-5 with similar structures were designed and synthesized.Among them,probe 5showed an ultra-fast response(19 s),high sensitivity(9.36 n M)and good selectivity to ONOO~-.Besides,with low biological toxicity and high biocompatibility,it can be successfully used for imaging ONOO~-in mitochondria and monitoring the therapeutic effect of hepatoprotective drugs on drug-induced liver toxicity.Chapter 4.Based on the model of two fluorophores and two reaction sites,a mito-target two-photon fluorescent probe CD-NA was developed for simultaneous detecting ONOO~-and GSH.With high sensitivity and ultra-fast response(18 s,30 s),it can detect ONOO~-and GSH respectively by two non-interfering detection processes and transmission channels.Also,CD-NA can effectively target mitochondria and has been successfully used for simultaneous two-photon imaging of ONOO~-and GSH in living cells.CD-NA is the first probe to perform two-photon imaging of ONOO~-and GSH simultaneously through dual fluorophores,which open up a new path for the crosstalk between ONOO~-and GSH.Chapter 5.We designed and synthesized a dual-fluorophore based ratiometric fluorescent probe CX for the detection of ONOO~-.The probe CX has high sensitivity(9.7 n M)and ultra-fast response(30 s),which would not be affected by other active substances interference.It has the potential for the application in biological systems.Chapter 6.The summary and prospect,including the summary of the experimental results of the four works,the analysis of the current advantages and disadvantages of the four probes,and the prospect of the fluorescent probes for detecting ONOO~-.