Determination Of Arsenic Based On Persistent Luminescent Nanoparticles And Gold Nanorods Optical Nanoprobes

Fluorescent chemical sensors is a special detector which can be aimed at targeted molecules in many fields including biology,medicine,environment and food based on fluorescence signal output information.Compared with traditional fluorescent dyes,fluorescent nanomaterials have distinctive advantages of photostability,high fluorescence,and easily surface modification,which have got great progress in fluorescent chemical sensors.Traditional fluorescent nanomaterials including noble metal nanoclusters,upconversion nanoparticles(UCNPs),quantum dots(QDs)and carbon quantum dots(CQDs)which cannot be used to detection in real-time in a large part because of the requirement of constant excitation,resulting in limitation of application in detection by real-time.The colorimetric probe based on gold nanorods is widely used in rapid detection of heavy metal ions because of its rapidity,accuracy and excellent selectivity.In this research,we developed PLNPs-PEI/DTT-AuNPs fluorescent probe and DTT-AuNPs colorimetric probe to detect As(?).The main contents are as follows:Firstly,we synthesized ZGGO(2n1.25Ga1.5Ge0.25O4:0.5%Cr3+)near-infrared long persistent nanoparticles by hydrothermal method combined with high-temperature calcination.The emission and excitation wavelength of as-prepared PLNPs is at 695 nm and 254 nm,respectively.After grinding and grading,we got the small size long persistent nanoparticles(60-70 nm),then we took the action of surface functionalization by sodium hydroxide(-OH),3-Aminopropyltriethoxysilane(-NH2,APTES),diglycolic anhydride(COOH-)and polyethyleneimine(PEI),respectively,which can get the PLNPs-OH,PLNPs-NH2,PLNPs-COOH and PLNPs-PEI,respectively.Finally,we take the action of characterization of the functionalized PLNPs.Secondly,we synthesized the Au nanorods(AuNPs)by seed growth method,the transverse absorption wavelength and the longitudinal absorption wavelength located on about 520 nm and 700 nm,respectively.Furthermore,the length and width of AuNPs(aspect ratio=2.9)are 36 nm and 12 nm,respectively.Then we took the action of surface functionalization by dithiothreitol to get the DTT-AuNPs.Finally,the PLNPs-PEI/DTT-AuNPs fluorescent probe and DTT-AuNPs colorimetric probe were used to detect the As(?).In order to improve the selectivity and sensitivity of detection,we took some optimization experiments including the synthesis optimization of AuNPs,the concentration of DTT,pH value,react time and the concentration of NaCl.Under the optimal conditions,the standard linear equation of PLNPs-PEI/DTT-AuNPs fluorescent probe is F/F0=0.01639[As]+1.01447 with the excellent detection range from 0.067 to 13.35?M,linear correlation coefficient R2=0.99734,the limit of detection(LOD)is 55 nM by rule of 3?.The standard linear equation of DTT-AuNPs colorimetric probe was ?A=0.00487[As]+0.02089 with the detection range from 0.10 to 10.01?M,linear correlation coefficient R2=0.99878,the limit of detection(LOD)is 38 nM by rule of 3?.Moreover,the precision of developed fluorescent probe and colorimetric probe were investigated by operating 11 repeated measurement of 2 ?M As(?)and all can reach 2.1%.Furthermore,the PLNPs-PEI/DTT-AuNPs fluorescent probe and DTT-AuNPs colorimetric probe are used to analysis the content of water sample come from local tap water,lake water and river water after treatment of centrifuge and membrane by quantitative spike recovery method.The quantitative spike recoveries of PLNPs-PEI/DTT-AuNPs fluorescent probe and DTT-AuNPs colorimetric probe are range from 94.6%to 105.0%and 95.2%to 100.4%,respectively.The above results show that the PLNPs-PEI/DTT-AuNPs fluorescent probe and DTT-AuNPs colorimetric probe can detect the As(III)with rapidity,selectivity and accuracy.