Study The Interaction Between CdTe Quantum Dots And Mitomycin C And Porphyrins Using Optical Spectroscopy And Analytical

In this paper, glutathione (GSH)-capped CdTe quantum dots (GSH-CdTe QDs) and tiopronin (TP) capped CdTe/CdS quantum dots (TP-CdTe/CdS QDs) were synthesized in aqueous solution, the shapes and sizes of the particles were determined by TEM, AFM. We utilized ultraviolet-visible (UV-vis) absorption spectra and fluorescence spectrometry to study the interaction between QDs and mitomycin C (MMC), protoporphyrin IX disodium salt (PPIX), and Chlorophyllin coppered trisodium salt (CCTS). Based on the interaction, we built a simple, high sensitive and new methold for determination MMC, PPIX and CCTS.The main results are as the following:1. A Study on the interaction between CdTe/CdS Quantum Dots with mitomycin C and its analytical applicationTiopronin (TP) capped CdTe/CdS quantum dots (TP-CdTe/CdS QDs) were synthesized in aqueous solution. The paper utilized ultraviolet-visible (UV-vis) absorption spectra and fluorescence spectrometry to study the interaction between TP-CdTe/CdS QDs and mitomycin C (MMC). With the optimum reaction conditions which was found to be at pH7.6with tris-HCl buffer solution, the quenched fluorescence intensity of TP-CdTe/CdS QDs was linearly proportional with correlation coefficient r=0.9991, and the detection limits were in the range of0.047-12μg/mL and the detection limit for MMC (3σ/K) was14.13ng/mL MMC will be quickly, simplely and conveniently, quantitatively detemination with this new method. This method has been applied to the determination of MMC in urine samples with satisfactory results.2.Determination of protoporphyrin IX disodium salt based on fluorescence quenching of GSH capped CdTe QDsAqueous glutathione (GSH) capped CdTe QDs with high fluorescence were synthesized in aqueous solution. We utilized ultraviolet-visible (UV-vis) absorption spectra and fluorescence spectrometry to study the interaction between GSH-CdTe QDs and protoporphyrin IX disodium salt (PPIX). With the optimum reaction conditions which was found to be at pH7.4with tris-HCl buffer solution, the fluorescence (FL) of CdTe QDs was quenched in the presence of PPIX. Under the optimal conditions, the quenched fluorescence intensity of CdTe QDs was linear in the range of1.6-16μg/mL with concentration of PPIX, and the detection limit (3a/K) was3.60×10-3μg/mL.In addition, the interaction mechanism of the CdTe QDs and PPIX was investigated. Accroding to the experimental results, this method could used as a rapid, simple and new method for quantitative determination of PPIX.3. Determination of chlorophyllin coppered trisodium salt based on fluorescence quenching of GSH capped CdTe QDsAqueous glutathione (GSH)-capped CdTe QDs with high fluorescence were synthesized in aqueous solution. We utilized ultraviolet-visible (UV-vis) absorption spectra and fluorescence spectrometry to study the interaction between GSH-CdTe QDs and chlorophyllin coppered trisodium salt (CCTS). The fluorescence (FL) of CdTe QDs was quenched in the presence of CCTS. Under the optimal conditions, the quenched fluorescence intensity of CdTe QDs was linear in the range of0.12-40μg/mL with concentration of CCTS, and the detection limit (3δ/K) was2.37×10-2ug/mL. The proposed method has been applied to the determination of CCTS in urine samples with satisfactory results.In addition, the interaction mechanism of the CdTe QDs and CCTS was investigated.4. Studies on the Interaction of Riboflavin with tryptophan by UV-vis, fluorescence spectroscopy and its analytical applicationThe ineraction between Riboflavin (RBF) and Tryptophan (Trp) was investigated by the methods of fluorescence spectroscopy and UV-vis absorption spectroscopy under physiological conditions.The fluorescence of Trp was quenched by RBF via dynamic quenching which was analyzed by Stern-Volmer relation. The value of Forster distance Ro (2.31nm) was obtained according to the Forster’s theory of non-radiative energy transfer. Under the physiological conditions, a linear relationship could be established between the quenched fluorescence intensity of Trp and the concentration of RBF in the range of5.8×10-7-2.0x10-5mol/L. The detection limit was1.80×10-7mol/L.The developed method was successfully applied for the determination of Riboflavin concentration in pharmaceutical samples. By comparison, testing results of this method was close to the national standard method.