A Novel Chemiluminescence Nanoprobe For Imaging Peroxynitrite

Chemiluminescence imaging is widely used in in vitro immunoassays,in vivo inflammation and tumor microenvironment imaging due to its advantages such as no external excitation light source and no autofluorescence interference.However,most of the traditional chemiluminescent systems have poor selectivity and emit visible light,which further restricts biological applications of chemiluminescence because of the severe scattering effect of biological tissues in visible light region.Based on these problems,this thesis found a new type of chemiluminescent molecule(O-pentacene)that responds to peroxynitrite for the first time,and constructed composite nanoprobes with different functions and applied them to detect endogenous peroxynitrite.We successfully solved the problems of chemiluminescence imaging including short luminescence wavelength and shallow penetration depth,and realized high selectivity,ultra-high sensitivity chemiluminescence imaging via Chemiluminescence resonance energy transfer.The research content of this thesis is divided into three parts:(1)We have discovered that O-pentacene dyes can react with peroxynitrite to produce chemiluminescence,and the mechanism of chemiluminescence was preliminarily studied.On this basis,a new type of chemiluminescence nanoprobe with micellar structure was constructed.The probe can detect peroxynitrite by chemiluminescence,and has the advantages of good water solubility,high selectivity and high sensitivity.(2)In terms of the short luminescence wavelength and weak luminescence intensity of the probe,we constructed a near-infrared chemiluminescence composite nanoprobe based on the principle of chemiluminescence resonance energy transfer.By doping chemiluminescence acceptor molecules in the micellar structure nanoprobe,the chemiluminescence wavelength is significantly extended and the chemiluminescence intensity is effectively improved.The composite probe realizes near-infrared chemiluminescence imaging with high sensitivity and high selectivity to detect peroxynitrite,enhances the tissue penetration of chemiluminescence,and provides important support for subsequent applications in in vivo imaging.(3)Based on the developed near-infrared chemiluminescence composite nano-probe,the research on the detection and imaging of endogenous peroxynitrite in living body is carried out.We used the composite nanoprobe to detect the endogenous peroxynitrite level in models of acute inflammation,peritonitis,tumor and drug-induced liver injury by in situ injection and system injection respectively,and found that the chemiluminescence probe can monitor the real-time changes of endogenous peroxynitrite levels in various diseases with high sensitivity and high selectivity.This provides a new imaging analysis tool for elucidating the pathological process of various peroxynitrite-related diseases.