Applacation Of Quantum Dots Fluorescent Probe In The Analysis Of Madicament And Heavy Metal Ion

Many analytical methods have used in the detection of drugs and toxic metal ions inrecent years, however, the interference caused by the matrix making the precision ofthese methods were not ideal, and some drugs were difficult to determine. In order todetection the content of toxic heavy metal ions and drug, it is necessary to find a sensitivechemical sensors. Quantum dot technology has a very high sensitivity as amulti-disciplinary technical, quantum dot photoluminescence properties relevant tosurface modification. Many metal ions have a significant impact on the optical propertiesof quantum dots through a different mechanism of action. It is increasingly applied to themetal ions and drugs, because of its high sensitivity in the quantitative analysis shows aunique advantage.This topic use the reaction of metal ions, drugs with quantum dots respectively tocause fluorescence quenching or fluorescence enhancement, and established the relationbetween the metal ion concentration, drug concentration and fluorescence intensitychange, so it can realize the determination of quantum dots for the content of metal ionsand drugs.In this paper,we synthesized CdS、CdTe and core/shell CdTe/CdS quantum dotswere in aqueous solution as the stabilizer to detect medice and heavy methal ion.Asfollow:1.A novel method for determination of Oxfloxacin has been developed based onarousing of the fluorescence of CdS QDs in aqueous solutions.The method was based onthe enhancements of scattering（△I） are directly proportional to the concentration of theoxfloxacin. A high sensitive method for the determination of oxfloxacin based on the system of CdS-oxfloxacin-SDS has been developed.The best experimentalconditions:reaction mediun is3.00mL pH=4.50buffer solution of NaAc-Hac; quantumdot of CdS is1.00mL; the surfactant is sodium dodecyl sulphonate（SDS）;the ractioncondition are room temperature,raction afrter15min to determinate.The systems wasmeasured at375nm.Under the optium conditions,the linear regression equation wasâ–³I=10.95C+14.345andâ–³I=0.4734C+25.538,the correlation coefficient was0.9994and0.9996.The detection limit is1.5×10^-4μg/mL.The linear range is4.0×10^-94.0×10-7kg/L.This method has been applied to the determination of samples directly with recovery of97.5%¹01.0%.2. A novel method based on the fluorescence intensity of CdTe are enhances by theconcentration of the pefloxacin mesylated and the existence of Al³⁺.A high sensitive methodfor the determination of pefloxacin mesylate based on the system of CdTe-Al³⁺-pefloxacinmesylate as proposed and validated. It has a satisfing result when used to determine inmedicines.The best experimental conditions:reaction mediun is2.00mL pH=5.80buffersolution of NaH2PO4-NaOH; quantum dot of CdTe is1.00mL; sensitization of Al³⁺is1.00mL1.00μg/mL;the raction condition are room temperature,raction afrter15min todeterminate.The systems was measured at570nm.Under the optium conditions,the linearregression equation wasâ–³F=12.122x（μg/mL）+0.5942,the detection limit is2.6×10^-3μg/mL. The linear range is0.04⁴.00μg/mL, the correlation coefficient was0.9975.This method has been applied to the determination of samples directly withrecovery of95.0%¹06.0%.3. Then studied of the reaction of Quantum Dot with NFLX according to thesensitization of Al³⁺.It showed a new way to determine microscle NFLX using CdTequantum dot as fluorescence probes. The best experimental conditions:reaction mediun is0.50mL pH=5.60buffer solution of NaAc-Hac; quantum dot of CdTe is1.00mL;sensitization of Al³⁺is1.00mL1.00μg/mL;the raction condition are roomtemperature,raction afrter15min to determinate.The systems was measured at580nm.Under the optium conditions,the linear regression equation wasâ–³F=21.735C +7.5585,the detection limit is4.4×10^-4μg/mL,the correlation coefficient was0.9926.Thelinear range is1.2×10^-32.4μg/mL. This method has been applied to the determination ofsamples directly with recovery of95.0%¹02.6%.4. The proposed method has been used for determination of trace amounts of silverion in synthetic samples.The method was based on silver ion quenching the fluorescenceintensity of CdTe/CdS in a buffer solution of citric acid-sodium citrate at pH=5.80andthe existence conditions of the surfactants of SDBS. The best experimentalconditions:reaction mediun is2.00mL pH=5.80buffer solution of citric acid-sodiumcitrate; quantum dot of CdTe/CdS is1.00mL;surfactants is3.00mL1.0×10^-4mol/L SDBS;the raction condition are room temperature,raction afrter15min to determinate.Thesystems was measured at604nm.Under the optium conditions,the linear regressionequation wasâ–³F=58.805c+1.9384,the detection limit is9.98×10^-4μg/mL,the correlationcoefficient was0.9988.The linear range is3.00×10^-37.00×10^-1μg/mL. This method hasbeen applied to the determination of samples directly with recovery of99.4%¹04.0%.5. A novel method for determination of Cu（Ⅱ） has been developed based onquenching of the fluorescence of CdTe/CdS QDs by Cu（Ⅱ） in aqueous solutions. Thebest experimental conditions:reaction mediun is2.00mL pH=4.60buffer solution ofNaAc-Hac; quantum dot of CdTe/CdS is1.00mL; the raction condition are roomtemperature,raction afrter15min to determinate.The systems was measured at608nm.Under the optium conditions,the linear regression equation wasâ–³F=31.773C+4.8528,the detection limit is9.90×10^-3μg/mL,the correlation coefficientwas0.9978.The linear range is0.01～1.00μg/mL. The method can be used in analysis ofpractical samples（tap water,rainwater,Yanhe water） with recovery of99.5%¹02.2%.