Investagation On Organocatalytic New Syetems Based On Carbon Nanotube And ATP

Due to specific high surface area, diminutive size, and active spots on the surface,carbon nanotube has many active spots on its surface and prone to interact with othermolecules. It has intrinsic enzyme catalytic activity and can catalyze the organicreaction which catalyzed by the corresponding enzyme before, broaden the thoughtsof biomimetic catalyst. Replace metal nanomaterials catalyst with carbonnanomaterials with comparable catalytic activity can reduce catalytic cost andenvironment pollution induced by metal ions. But its enzyme-mimic activity was justused for optical analysis and directly catalyze organic reaction need high temperatureand pressure with stringent reaction condition.DNA-templated organic synthesis could help biocompatibility organic reactionto take place under nanomolar concentration, however it is highly dependent on thesequence of DNA template and limit its sphere of application. In this thesis, we usedcarbon nanotube’s enzyme-mimic activity or instead of metal catalyst to catalyze twokinds of organic reactions, at the same time, introduce an interchain Staudingerreduction induced by bio-related molecules, set up a new system for organocatalysis.The contents of the thesis are as followed:(1) Based on the intrinsic peroxidase catalytic activity of carbon nanotube, wecarry out carbon nanotube catalyze the oxidize of o-phenylenediamine toproduce2,3-diaminophenazine after the addition of hydrogen peroxide. Withoutcarbon nanotube，color of reaction system changed negligible. Upon the addition ofcarbon nanotube, the color of reaction system changed from achromatism to yellowaccompanied the characteristic absorption peak of product increased. We alsodiscussed the dispersed state and aggregated state of carbon nanotube and its impacton the catalytic activity.Single DNA can disperse carbon nanotube and duplex DNAcould not, the dispersed state of carbon nanotube has higher catalytic activity as theaggregated state will reduce its catalytic efficiency. This method establishes thereaction that uses carbon nanotube instead of enzyme to catalytic oxidation forsynthetize medical intermediates and of great significance for industrial application.(2) Carbon nanotube was directly used to catalyze the kind of Knoevenagelreaction with higher product conversion. Choose the typical Knoevenagel reactionbetween benzaldehyde and malononitrile or furfural and malononitrile as model, takecarbon nanotube with carboxylation as catalyst, room temperature and use DMF as solvent, carbon nanotube have better catalytic activity. Compared with the reactionsystem without carbon nanotube, the yield of product increased several times. Afterthe reaction carbon nanotube can extraction and separation from the reaction systemeasily for reusable.(3) Staudinger reaction cannot occur under nanomolar concentrations limit theirapplication, especially bio-orthogonal reaction for modificaiton of protein and nucleicacid. We synthesized a7-azidocoumarin derivate whose fluorescence is quenched byintroduce an azide group. Upon addition of triphenylphosphine (TPP), the Staudingerreaction take place and fluorescence recover with mM concentration of TPP. Butunder nanomolar concentration, the Staudinger reduction cannot occur. We report theapplication based on an ATP assisted sandwich panel structure which after addition ofATP, the specific interaction between ATP and aptamer draw the distance between twodivided ATP aptamer which conjugated with7-azidocoumarin and TPP, then catalyzethe Staudinger reaction under lower concentration and get fluorescent7-aminocoumarin as signal product for the detection of ATP. The fluorescence signalof product related to ATP concentration and has good selectivity.