Visual Detection Of Hydroxyl Radicals And Vancomycin

Part Ⅰ Establishment and application of a new colorimetric detection method for hydroxyl radicalpurpose:1.Design a simple,sensitive and visual method for detecting hydroxyl radicals.2.Determination of free radicals during the activation process of artemisinin and dihydroartemisinin by colorimetrymethod:1.The establishment of Griess response and standard curve.2.Detection of hydroxyl radical by Fenton reaction.3.Detection of hydroxyl radicals in water decomposition.4.Detect the hydroxyl radicals of artemisinin compounds during activation.result:1.The relationship between the absorbance at 540 nm and the concentration of nitrite established a standard curve for the Griess test.2.This method can sensitively and selectively detect ·OH radicals in the Fenton reaction with a detection limit as low as nanomolar.At the same time,it successfully detected the ·OH radicals in the water radiolysis process.In addition,we successfully Heme-catalyzed release of ·OH free radicals was detected in two classic antimalarials,Art and DHA.conclusion:Based on the Griess test,a new strategy for colorimetric detection of hydroxyl radicals was developed.Ability to quickly and visually detect hydroxyl radicals.And it is proved that artemisinin and dihydroartemisinin in the artemisinin drugs do have a free radical theory in the activation process,which indirectly proves the free radical theory of artemisinin activation.Part Ⅱ New fluorescent probes for vancomycin analysis and imagingpurpose:1.Design a new type of selective and sensitive probe to detect the important antibiotic vancomycin(Van).2.Explore the detection of vancomycin in target probes in buffer,synthetic urine,and human serum.3.In vivo imaging of target probes.4.Investigate the mechanism of target probe response to vancomycin.method:1.Prepare the polypeptide chain by solid phase synthesis(SPPS),select coumarin and fluorescein as dual fluorescent reporter molecules,integrate them on the polypeptide,and prepare control molecules at the same time.2.Use the synthesized probe molecules to detect vancomycin in buffer,synthetic urine,and human serum,and explore the effects of response degree,selectivity,sensitivity,and pH.3.Cultivate zebrafish experimental model,simulate the polluted environment of vancomycin,and use target probes for in vivo imaging.4.Using molecular docking,molecular dynamics(MD),to quantitatively measure the number and distance of hydrogen bonds formed between the probe and Van to explore the mechanism of action.Photochemical methods were used to calculate the fluorescence lifetime of the probe molecules and the energy transfer efficiency between the fluorophores.result:1.One target probe and two control probes were obtained through solid-phase and liquid-phase synthesis,named P1,P2,and P3,respectively.Confirmed by NMR and MS characterization.2.The P1 probe showed a good linear relationship when detecting vancomycin in buffer and synthetic urine.The minimum detection line in synthetic urine was 92.8nM,and it showed the potential to detect vancomycin in serum.Specific response to vancomycin,excellent response to vancomycin under neutral or weak alkaline conditions.Loss of detection ability under acidic conditions.P2 and P3 probes do not respond to van3.P1 probe can detect vancomycin in zebrafish,and the probe is mainly distributed in the gastrointestinal tract of fish,and obvious green fluorescence can be observed.4.We found that the response of P1 probe to Van is not a typical FRET mechanism,but self-quenching of fluorescence caused by fluorophore stacking.When Van is bound to D-Ala-D-Ala peptide,fluorescence may be due to fluorophore.The decomposition was turned on,and our conjecture was confirmed by TEM imaging and dynamic light scattering(DLS)measurement.conclusion:1.Developed a new type of fluorescent probe for the detection of vancomycin with good selectivity and high sensitivity.2.The lowest detection limit in urine of the new fluorescent probe is 92.8nM.This makes it possible to apply it in clinically relevant areas.3.The P1 probe was successfully applied to the detection and imaging of Van in zebrafish.4.Our strategy provides new information on structure-response relationships,which may be beneficial for the design of fluorescent proportional probes.