Nano-fluorescence Sensing Research Of Active Species In Cells Or In Vivo

Small active molecules in cells,such as reactive oxygen species and metal ions,are closely related to the occurrence and development of diseases.The excess superoxide anion(O₂^·-)will induce a variety of diseases,cause harm to the health.Due to the limitation of sensitivity and reversibility,the existing imaging of superoxide anion(O₂^·-)in cells and living bodies is basically achieved by adding external stimuli,and the endogenous superoxide anion(O₂^·-)content of the biological system can not be analyzed in real time and in situ.When the ion balance of the intracellular variable iron pool is destroyed,many metabolic processes,such as oxygen transport and storage,redox and so on,will lead to the occurrence of many diseases.Therefore,the development of analytical methods for intracellular iron（III）is of great significance for studying the occurrence and development of diseases.In order to solve the above problems,we developed two types of fluorescent nano probes,using the redox properties of the active site Te,to prepare the functionalized fluorescent carbon points,and study the changes ofO₂^·-level in the strenuous exercise,noise interference and depression of mice,and combine the histamine through the glutaraldehyde bond to the BSA modified gold nanocluster table.A simulated transferrin fluorescent nanoparticle probe was designed and applied to detect and analyze Fe³⁺in the process of cell iron death.The main contents of this paper are as follows:1、According to the very low concentration of O₂^·-in cells and living bodies,it is easy to transform,and there is no suitable material and method to detect the true concentration of superoxide anion in cells and in vivo.We use the active site of Te oxidation reduction properties was designed and fabricated with ultra high sensitive function of fluorescent carbon dots（Te-CDs）on the O₂^·-.Te-CDs on O₂^·-and showed good reversibility and instantaneous response,the detection limit can achieve 8.0 pM.Two photon imaging points were used for O₂^·-carbon in normal living cells in tumor tissue and,through the test image,we can clearly see that Te-CDs can detect O₂^·-and no external stimulation of endogenous O₂^·-.Therefore,carbon on O₂^·-detection showed the characteristic of high sensitivity and can detect the content without external stimulation of endogenous O₂^·-,and the.By two-photon fluorescence imaging,we found that the mice in acute strenuous exercise and emotional changes significantly increase their body O₂^·-level.Finally,we discuss the use of Te-CDs imaging in depression mice brain,can instantaneously and dynamically display the change of O₂^·-concentration and depression in mice.2、For now Fe³⁺almost all probe fluorescence quenching and the detection limit is not up to the requirements of the endogenous,gold nanoparticles we design and a new stable synthesis,the histamine and BSA-Au by glutaraldehyde crosslinking polymerization of nanoclusters by hydrolysis of chelation and Fe³⁺catalyzed imine bond imidazole and Fe³⁺reaction makes Au NCs obtained from gold nano composite materials released,so the fluorescence enhancement,has a good selectivity to Fe³⁺,the lowest detection limit is 18.7pM,this is the detection of intracellular Fe³⁺fluorescence imaging technology can achieve the highest sensitivity.The experimental results show that the nano probe can be applied to change the content of Fe³⁺in the process of detecting and imaging variable iron pool and iron death.This study not only provides a sensitive imaging method for intracellular Fe³⁺,but also provides a new method for the study of cell function regulating Fe³⁺in cells.