Aptamer-adjusted Doped-N Carbon Dots Catalytic SERS/Fluorescence Spectrometry For Detection Of Isocarbophos

In this paper,the research progress of aptamer analysis and surface enhanced Raman spectroscopy,fluorescence spectroscopy was introduced.The advances in the study of isocarbophos(IPS)analytical methods were summarized,and a new surface enhanced Raman scattering(SERS)/Fluorescence method was developed for the detection of isocarbophos.This paper briefly describes the research content and significance.The specific research work mainly in the following aspects:Nitrogen-doped carbon dot(CDN)has a strong catalytic effect on the oxidation of tetramethylbenzidine(TMBox)with strong SERS activity at 1615 cm-1 in the silver nanosol substrate.The aptamer(Apt)can be adsorbed on the surface of CDN that its catalytic activity can be inhibited,the generated TMBox reduced,and the SERS intensity and absorption both weakened.When the target molecule isocarbophos(IPS)was added,it forms a stable Apt-IPS conjugate and free CDN that catalytic activity restored,and the SERS and absorption enhanced linearly.Based on this,we proposed a new SERS quantitative analysis method for the determination of 0.03-1.5 ?g/L IPS with a detection limit of 0.011 ?g/L.The strongly fluorescent and highly catalytic N-doped carbon dots(CDN)were rapidly prepared by a microwave irradiation procedure and were characterized by electron microscopy(EM),laser scattering,infrared spectroscopy(IR),and by their fluorescence spectrum.It was found that the CDN had a strong catalytic effect on the fluorescence reaction of 3,3',5,5'-tetramethylbenzidine hydroxide((TMB)–H2O2)which produced the oxidation product of TMB(TMBOX)with strong fluorescence at 406 nm.The aptamer(Apt)was adsorbed on the CDN surfaces which weakened the fluorescence intensity due to the inhibition of catalytic activity.When the target molecule isocarbophos(IPS)was added,it reacted with the Apt to form a stable conjugate and free CDN which restored the catalytic activity to enhance the fluorescence.UsingTMBOX as a fluorescent probe,a highly sensitive nanocatalytic method for determination of0.025–1.5 ?g/L IPS was established with a detection limit of 0.015 ?g/L.Coupling the CDN fluorescent probe with the Apt–IPS reaction,a new CD fluorescence method was established for the simple and rapid determination of 0.25–1.5 ?g/L IPS with a detection limit of 0.11 ?g/L.