| Malondialdehyde,is regarded as typical biomarker of lipid peroxidation has attracted much attention long ago.Alteration of malondialdehyde level in the biological often reflects pathological changes,which has been verified in various types of illness.Although many detection methods have been used in malondialdehyde test,but almost all those methods suffer from rather tedious chemical derivatizations usually under harsh conditions like strong acidity and/or elevated temperature;thus,they are only applicable in body fluid samples like serum and urine.The highly selective small molecule fluorescent probe enable direct visualization and minimally interfere with the corresponding biological process,thus,they can be well applied to the relevant detection in vivo and vitro.But the development of the high selective fluorescent probe for malondialdehyde detection is not ideal.Therefore,it is very necessary to design and synthesize fluorescent probes for the detection of malondialdehyde.The malondialdehyde can react with hydrazine to form five-membered ring pyrazole compounds and the five-membered ring is relatively stable.Two fluorescent turn-on probe with high selectivity for the detection of malondialdehyde were designed and synthesized by using the specificity of the reaction between hydrazine and malondialdehyde.This paper is divided into the following three chapters:Chapter Ⅰ:This paper mainly introduces the development of fluorescent reagents and fluorescent probes for the detection of aldehydes.Chapter Ⅱ:We have constructed a rhodamine hydrazide fluorescent probe RB4-1,with a synergistic the specific reaction of benzohydrazide with malondialdehyde and the ring-opening reaction of rhodamine hydrazide compounds,which achieves high sensitivity and selectivity for malondialdehyde detection.In the weak acidic environment,the probe RB4-1 was treated with benzohydrazide as the recognition group and reacted with malondialdehyde to form rhodamine-pyrazole compound,the absorbance at 575 nm and fluorescence intensity at 600 nm were significantly enhanced owing to large conjugated πbond system in the probe molecule was recovered.The probe RB4-1 has no response to common metal ions,other small molecule aldehydes and some biothiols under the conditions of malondialdehyde detection,showing good selectivity to malondialdehyde.Using the probe,we successfully achieved the detection of malondialdehyde in the cells.After the change of the test conditions,the probe RB4-1 could also be applied to the detection of malondialdehyde in vitro samples.The results indicate that the probe RB4-1 can be used for malondialdehyde detection in different biological systems,has a good application prospects.Chapter Ⅲ:In this study,we have developed a fluorogenic MDA probe,4-hydrazinyl-7-nitrobenzofurazan(NBDH).The reaction between NBDH and MDA in acidic conditions yields a highly fluorescent product,4,5-dihydro-lH-pyrazole derivative(NBD-P1).The MDA detection range of our probe NBDH falls between 0.1 and 20 μM,and the corresponding detection limit amounts to 7.2 nM(38).NBDH also demonstrates a high selectivity toward MDA over other aldehydes and biologically relevant molecules,and proves to be an excellent MDA assay in biological fluids. |
