Aqueous Synthesis Of Quantum Dots For Drug Detection

Research background and objectiveThe critical point for drug detection is to obtain a novel method with accuracy,high sensitivity,quick,inexpensive,facile and good stability.Currently,the most commonly used for drug detection is high performance liquid chromatography and high performance liquid chromatography-mass spectrometry.This method has high sensitivity and accuracy,but also exist some backdraws such as high instrument cost,complex operation and time-consuming.The fluorimetric method has been increasingly employed in drug detection areas due to its simplicity,selectivity,and,cost-effective nature.Quantum dots(QDs)just come to overcome these limitations and attract much attention of researchers in drug detection fields.QDs,which have synthesized by special elements from Ⅱ/Ⅵ or Ⅲ/Ⅴ,are a kind of semiconductor,have excellent fluorescence characters(e.g.,stable,large stokes shift,narrow,and tunable emission spectra with broad excitation spectra)compared with conventional organic fluorescent dyes.It is widely used in the fields of drug detection as for these advantages: the aqueous phase synthesis is simple,easy surface modification,easy to characterize as well as the special physical and chemical properties.Research methods and resultsThe purpose of this dissertation is to explore the RTP properties of Mn-doped ZnS quantum dots and their application for drug detection.The main results are outlined as followings:1、In this work,a facile and less cost method for the determination of gentamicin sulfate is reported.The thiogycolic acid capped CdTe quantum dots were synthesized in aqueous phase.The transmission electron microscopy,infrared spectroscopy and fluorescence spectroscopy were used to characterize the particle size and shape,the surface chemical group and the fluorescence property of the quantum dots.The fluorescence emission peak at 607 nm and the TEM images displayed CdTe of about4.0 nm were synthesized.The fluorescence quenching effect of gentamicin sulfate toCdTe quantum dots was researched,and a new method for the detection of gentamicin sulfate using CdTe quantum dots as fluorescent probes was established.Under the optimal conditions,CdTe quantum dots were successfully applied to the sensitive detection of gentamicin sulfate in water,and a linear relationship was obtained to cover the concentration range of 0.10 ~ 2.00 mg/L with a correlation coefficient of 0.9989,which was best described by a Stern-Ⅴolmer equation.The proposed method can be used for the determination of gentamicin sulfate with satisfactory results.2、A simple,inexpensive and sensitive method was established for determination of gentamicin sulfate using mercaptopropionic acid(MPA)capped Mn-doped ZnS QDs.The MPA-capped Mn-doped ZnS QDs of various sizes were successfully synthesized in aqueous medium and characterized by fluorescence spectroscopy.Meanwhile,different effect factors on the detection were investigated,including buffer type,order of addition,reaction time and quantum dots concentration.The room-temperature phosphorescence(RTP)of 3-mercaptopropionic acid(MPA)-capped Mn-doped ZnS quantum dots could be remarkably enhanced by the addition of gentamicin sulfate.Based on the above finding,a simple,cost-effective and sensitive method for rapid detection of gentamicin sulfate in biological fluids was successfully designed.Under the optimized conditions,the change of RTP intensity was proportional to the concentration of gentamicin sulfate in the range from 0.10 to10 mg/L,with a correlation coefficient of 0.9985.The primary aim of this study was to achieve the purpose of monitoring the treatment by measuring the concentration of gentamicin in urine.The method was successfully applied to detect gentamicin sulfate in human urine samples with satisfactory results,and the recovery ranged from 98 to104%.3 、 In the current work,using the above synthesized Mn-doped ZnS QDs as representative nanoparticles to detect aminophylline in the room temperature.During the experiment,different effect factors on the detection were investigated,including buffer type,buffer pH,order of addition and reaction time.The RTP of3-mercaptopropionic acid(MPA)-capped Mn-doped ZnS quantum dots could be remarkably enhanced by the addition of aminophylline.Based on the above finding,afaxile method for rapid detection of aminophylline was successfully designed.Under the optimized conditions,the RTP intensity change was linearly proportional to the concentration of aminophylline in the range 2 ~ 30 mg/L,with a correlation coefficient of 0.9962.The RTP property of Mn-doped ZnS quantum dots was explored to develop a novel method for facile,rapid,cost-effective detection of aminophylline in drugs.The proposed method can be used for the determination of aminophylline with satisfactory results,and the recovery ranged from 101% to 104%.4 、 A selective system was developed to detect amikacin sulfate by using MPA-capped Mn-doped ZnS QDs as a sensitive RTP nanosensor.During the experiment,different effect factors on the detection were investigated,including order of addition and reaction time.The RTP of 3-mercaptopropionic acid(MPA)-capped Mn-doped ZnS QDs could be remarkably enhanced by the addition of amikacin suifate.Based on the above finding,a simple,cost-effective and sensitive method for rapid detection of amikacin sulfate in biological fluids was successfully designed.Under the optimized conditions,the change of RTP intensity was proportional to the concentration of amikacin sulfate in the range from 0.05 to 5 mg/L.The Mn-doped ZnS QDs based RTP method did not need the use of deoxidants and other inducers,and allowed detecting amikacin sulfate in urine and serum without interference from other ingredients.The proposed method can be used for the determination of amikacin sulfate in urine and serum with satisfactory results,and the recovery ranged from 95% to 104%.