Synthesis Of YVO₄:Eu Fluorescent Nanoprobe And Its Apllications In The Determination Of Brilliant Blue And Tryptophan

In recent years,the synthesis of rare earth luminescence nanoparticles and their appllications in markers have received extensive attentions.They have several advantages such as long fluorescence lifetime,large stokes shift,narrow emission line and pure luminescent color,so they have been successfully applied in biomolecular detection,immunoassay,cell imaging and so on.In this paper,YVO4:Eu nanoparticles were synthesized and their applications were studied.PEI(polyethylenimine)modified YVO4:Eu nanoparticles were synthesized by solvothermal method.The optimal conditions to synthesize the YVO4:Eu nanoparticles were investigated.The prepared nanoparticles were positively charged,good water solubility,and the luminescence intensity of the as-prepared nanoparticles were strong and stable.The nanoparticles were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM)and infrared spectrometer(IR).The results showed that the as-prepared nanoparticles were about 15 nm.They were tetragonal crystals with good crystallinity.In addition,the nanoparticles were coated with PEI on the surface.Using YVO4:Eu nanoparticles as an energy donor,brilliant blue(BB)as an energy receptor,a new luminescence resonance energy transfer system to detect BB was built.The linear regression equations were lgl=2.95-2.76c(R=0.9979)and lgI=2.92-0.18c(R=0.9943)(the unit of c is mg·L-1),the linear ranges were 2.50×10-6?2.50×10-4 g·L-1 and 2.50×10-4-2.50×10-3 g L-1,repectively.The detection limit was 1×10-6 g·L-1.This method was used to detect BB in drink and candies,and recoveries were 104%-105%and 93.4%?95.6%,respectively.Based on the inner filter effect between YVO4:Eu nanoparticles and tryptophan,we built a new method to detect tryptophan.Under the optimum conditions,when the concentration of tryptophan was in the range of 4.00×10-6?4.00×10-4 mol·L-1,the linear regression equation was lgI= 1.96-2.84c(the unit of c is mmol·L-1)with a correlation coefficient of 0.9970 and the detection limit was 1×10-6 mol·L-1.This method was used to detect tryptophan in human serum and commercial soy sauce with recoveries in the range of 96.8%-103%and 95.2%-97.3%,respectively.The results proved that the method was accurate and reliable.