Preparation Of Quantum Dots/Nano Fiber Fluorescent Probes And Detection Research Of Active Substance

CdTe quantum dots were synthesized in aqueous solution with thioglycolic acid as the stabilizer, the reaction between tellurium powder and sodium borohydride as the precursor, with cadmium chloride aqueous solution under the condition of anaerobic reaction. In addition, we can acquire different colors and sizes by changing the reaction time. The samples were characterized by UV、FL、TEM、SEM. All the results indicate that the size distribution and stability of the CdTe quantum dots were good.A novel determination of chloramphenicol has been developed based on quenching of the flurescence of CdTe QDs by chloramphenicol in aqueous solutions. CdTe quantum dots and electrostatic spinning PLA were synthesised with electrostatic spinning in certain proportion, using the as-prepared nanometer fiber membrane to detect chloramphenicol, Characterizating with Transmission Electron Microscope(TEM), scanning electron microscopy(SEM),fluorescence spectrophotometer, fluorescence microscope. The results showed that the quantum dots had been fixed on the fiber, not reunited together, and could have quenching effect on chloramphenicol, so as to realize the purpose of the testing.Through electrostatic spinning of PLLACL, fluorescence emission spectra of green CdTe quantum dots was coated in the lining of the nanofibers, red CdTe quantum of fluorescence emission spectra dots with negatively charged were self-assembly combined with strong cationic PDDA through electrostatic interaction, preparing the double launching CdTe quantum dots fluorescent probe.The outer red CdTe quantum of fluorescence emission spectra dots could couple chloramphenicol molecular, and then the intensity of fluorescence quantum dots turned lower as a result of the resonance energy transfered.The green CdTe quantum dots located in the internal was not affected by chloramphenicol.The PLLA-CS-QDs-NO composite fibers are prepared by means of coaxial-electrospinning, in which the PLLACS was used as the filament materials. The fibrous PLLA-CS-QDs-NO composite could release NO under UV and the released NO could be real-timed detected. The samples have been characterized by TEM, UV, FL, EDS.The results show that the fibrous could release NO under UV and the QDs are quenched by NO, based on fluorescence quenching mechanism. The work provides a novel fibrous NO release and detection system which have great potential to be used in various biomedical applications.