Synthesis Of Fluorescent Probe And Its Application In Food Detection And Tumor Imaging

Food is the premise and basic guarantee for human survival,food safety is immediately concerned to people's health.In recent years,the illegal or excessive use of food additives,melamine in dairy products,the residue of plasticizers exceed the standard,antibiotics and hormone abuse and other food problems emerged constantly.Spectrum contains abundant physical and chemical information.Spectral analysis technology has been widely used in environmental monitoring,food detection,chemical analysis,life science and other fields because of its rapid,simple,non-invasive and efficient analytical characteristics.Among all spectral detection techniques,fluorescence probe remain the characterisrics of high sensitivity,convenient use and low cost of spectral analysis,but also can be used in living systems with minimal perturbation to support overall spatiotemporal information.This makes the fluorescence probe could detect the analyte with high sensitivity and selectivity in vitro,in virtue of laser confocal scanning microscope,it could also monitor analyte in vivo.By intake of food containing natural antitumor components,antitumor active substances play an important role in inhibiting tumorigenesis,causing apoptosis of tumor cells or improving tumor microenvironment.It is one of the research topics of food nutrition researchers so far.However,when evaluating the antitumor effect of antitumor active substances,researchers need to determine various indexes,which leads to the unreliability of the conclusion,and the results are easily affected by subjective factors.Therefore,it is particularly necessary to evaluate the tumor microenvironment by simple and reliable means,in which combine with the characteristics of "real-time trace,online and visual imaging" of fluorescence probe.This method will blaze the trail in the detection of tumor hypoxia.The main results of this reseach are given below:1)A new near-infrared fluorescence offon probe,1,was developed and applied to fluorescence imaging of benzoyl peroxide(BPO)in vitro and in vivo.By conjugating the hemicyanine skeleton(synthesised via the decomposition of IR-780)and arylboronate(recognition unit),the phenylboronic acid pinacol ester can be oxidized by BPO,followed by hydrolysis and 1,4-elimination of o-quinone-methideand to release fluorophore.This probe achieves high selectivity and sensitivity towards BPO,and exhibited superior analytical performance such as near-infrared fluorescence emission over 700 nm as well as.Notably,the probe is cell membrane permeable,and its applicability has been successfully demonstrated for monitoring BPO in living Hela cells and zebrafish.The superior properties of the probe make it of great potential use in other biosystems and in vivo studies.2)A ratiometric near-infrared fluorescence probe is developed and applied to fluoride anion(F-)detection in potable water and white flour as well as fluorescence imaging in vivo.The proposed probe not only shows a linear ratiometric(F740/F690 nm)fluorescence response but also possesses near-infrared wavelengths to F-with a detection limit of 0.2 ?M.Moreover,the designed probe displays high selectivity toward F-,which makes it feasible for F-detection in potable water and white flour.More importantly,applied to monitor F-in living HepG2 cells and male BALB/c mice,the probe indicates good biocompatibility and low cytotoxicity.3)Two hypoxia-sensitive probes(AXNO2 and AXNN)were designed and synthesized.The probes were designed by introducing hypoxia activatable p-nitrobenzyl or azo moiety as the sensing unit to the hemicyanines with an amino group(AXPI),both of two probes could be specifically reduced by hypoxia up-regulated enzymes.In tumor cells and tissues,both of the probes exhibitied superior analytical performances such as NIR fluorescence emission,high stability,passive accumulation and fast clearance.Interestingly,such a detection has been first used in differentiate HepG-2 and 4T1 cells through fluorescence signals.The results indicate that a set of biological markers,rather than a single one,seem to be more reliable for prognostic tumor hypoxia.This method may be of great potential use in cancer and other relevant disease diagnoses.