Research Of Au NPs Doped Inverse Opal Photonic Crystal Sensor For Parathion Rapid Detection

In recent years,food safety accidents caused by pesticide residue and veterinary drug residues occur frequently,which influencing people's health seriously.Food analytic detection techniques,as an effective means to detect these chemical residues,play an important role in the regulation and supervision of food safety.Nowadays,the detection of chemical residues in food mainly depends on lab equipment.Although these methods show high sensitivity and specificity,but very few of them can fully satisfy real-time detection requirements of the current food safety,in terms of rapid,agile,convenience,etc.So,this dissertation applied the Molecular Imprinting Technique with specific adsorption combined with rapid and visual photonic crystal(PC)technique,using signal amplification of Localized Surface Plasmon Resonance(LSPR),to fabricate the rapid response,agile PC sensor for pesticide molecules detection.Au nanoparticles,Ag nanoparticles and Au-Ag alloy nanoparticles were synthesized by “hot colloidal” approaches with the reducing action and the stabilizing action of oleylamine and oleic acid.The nanoparticles get better monodispersity than those in aqueous phase.According to the comparison of LSPR spectrums of the nanoparticles,we knew that the absorption peak positions have linear relation with the Au content,and achieved tunable LSPR without changing the shape of nanoparticles.Besedes,the exchange of ligands on the surface of Au-Ag alloy nanoparticles is successful with normal propyl alcohol as the solvent,which makes the alloy nanoparticles disperse in polar solvent.The application of the Au-Ag alloy nanoparticles will be expanded.A novel Au-MIP IO PCs has been successfully prepared by adding Au nanoparticles(Au NPs)into the MIP IO PCs,based on molecularly imprinted technology and PCs technique for the visual detection.In our experiment,Parathion was chosen as target molecules.During the process of Parathion eluted,we analyzed the destruction of Au-MIP IO PCs by the eluent in different elute times,and optimizing the best one.Besides,the addition of cross-linking agent EGDMA was also optimized,so that we can get the detection result of Au-MIP IO PCs.We compared the detection results of Au-MIP IO PCs,MIP IO PCs,Au-NIP IO PCs and NIP IO PCs,which showed that the diffraction peak of corresponding Au-MIP IO PCs show obvious red-shift and intensity decrease,and the signal amplification of Au NPs is obvious,compared with MIP IO PCs.And the non-molecular imprinted sensor had no response without molecularly imprinted holes,even though Au NPs were added.In addition,various molecules have been used as target molecule to fabricate kinds of Au-MIP IO PCs.These Au-MIP IO PCs also showed excellent non-specificity,selectivity and recycling performance.