| Living beings were constructed with some single cells, and substances inside are most important to cell's surviving, reproduce, damage, and death. Therefore, studies upon functions of organisms from single cells level and molecules level, are spotlight and significant in present days. Cultured cells kept up some characteristics of tissue. The model of cells in hypoglycemia and hypoxia can mimic the morbid state of intracorporal tissue or organs in the absence of other species, such as neutrophils and nerve corpuscles. In order to fight for myocardial ischemic necrosis and protect myocardium, lots of model studies were performed for mechanism research. In this paper, three parts of work have been performed in the thesis following an overall review:Chapter One: Critical ReviewsA critical review with regard to the cells assaying was presented, including the study of cell with traditional methods, application of analytical chemistry towards cell analysis, the development of detection technology for messengers of biological systerm, especially, the CE, micro-column separation, microelectrodes. In addition, the characteristic, biosynthesis and biological functions of some important messenger molecular, such as, nitric oxide, superoxide, purine and Cyt C was also reviewed.Chapter Two: Preparation of Nitric Oxide Microsensor and Its Application towards Cells AnalysisThe aim of this work was to fabricate microelectrodes as a current approach for the in situ monitoring of nitric oxide release from living cells stimulated by some exogenic agonists. For the purpose, a novel sensitive, selective and stable nitric oxide (NO) microsensor is constructed, which is modified by nano Au colloid and Nafion. Determining by Atomic Forced Microscope, the diameter of Au colloid particles is from 7 to 14 nanometers. The detection of NO is based on the nano Au particles catalysis ofNO oxidation at an anodic potential of +0.74V (vs. SCE). The microsensor showed a low detection limit, high selectivity and sensitivity for NO determination. The oxidation current (measured by differential pulse amperometric technique) was linear with NO concentration ranging from 1.0x10-7 to 4.0x10-5 mol/L with a calculated detection limit of 5.0x10-8 mol/L (S/N=3). Using the microsensor, the direct, real time production of NO in the smooth muscle cells and myocardial cells was continuously measured.Chapter Three: Fabrication of Superoxide Microsensors and its Application toward Endothelial CellsA novel superoxide microsensors based on platinum/palladium microparticles and electropolymerized pyrrole was fabricated for the measurement of extracellular endothelial cells superoxide. The Pt/Pd-PPy modified microsensors were evaluated as superoxide sensor. The amperometric responses to superoxide were monitored at the potential of O.OOV(vs SCE) in HBSS. The sensor was proved to have a high sensitivity, selectivity and short response time. The detection limit is 12 nmol/L (S/N=3). The life period (at least 1 month) of sensors is longer than that of enzyme electrodes. The potential interference from some endogenous electroactive substances in biological system, such as H2O2, UA, neurotransmitters and their metabolites, at the concentrations higher than those in biological system, could be eliminated by further coating the Pt/Pd modified electrode with a poly pyrrole fihn. The method was applied to the measurement of superoxide production in endothelial cells.Chapter Four: Study on the Change of Purin during the Process of Injury and Respairation of Myocardial Cells(1): A novel hypoxanthine (Hx) microsensor was constructed. In this work, Nafion Xanthine oxidase and Au colloid were immobilized on the surface of Pt microelectrode, respectively. The enzyme biosensor displayed a quick and sensitive response to Hx. In physiological condition, the biosensor showed a low detection limit, high selectivity and sensitivity for Hx determination. The oxidation current(measured by i-t) was linear with Hx concentration ranging from 2.0x10...
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