| In recent years,the continuous exposure of food safety incidents has made people aware of the importance of food safety.Developing fast,sensitive and efficient detection methods is en effective measure to ensure the quality and safety of food.In order to further expand the detection method of food contaminants,in the field of food analysis,the combination of different methods is also required for sensitive detection of specific analytes.Since 1990s,the rapid development of surface enhanced Raman scattering technology,coupled with its in-situ,nondestructive,anti-water interference and high sensitivity,has made it widely used in the field of food safety,but its selectivity is far from enough for analysis.Molecularly imprinted ploymers which prepared by molecularly imprinted technology has good selectivity,which made it widely applied in analysis field as the increasing maturity of preparation technology.Based on the above background,this paper will combine SERS which has high sensitivity and MIT which has high selectivity,with noble metal Au and Ag as carriers which have strong SERS enhancement effect,two kinds of molecular imprinting complexes were prepared for the sensitive and specific detection of bisphenol A and patulin,respectively.The specific research contents are as follows:1.Preparation of Au NPs surface imprinting SERS substrate based on the first-generation hotspots and its application for PAT detection in food samples.Using Au NPs as carriers,which have the first-generation hotspots to provide SERS performance,and the optimal size is 50 nm;Then,the MIPs which can specificly detect PAT were synthesized by HRP-initiated free-radical polymerization and surface imprinting,using4-VP as functional monomer,PDA as crosslinking agent and PAT as template molecule.The MIPs-SERS substrate has a high sensitivity for the detection of PAT,the detection limit is 5.37×10?1212 mol/L and the linear range of this substrate is 7.00×10?1212 mol/L5.00×10?88 mol/L.Specific experiments with PAT structure analogues for interferon showed that the MIPs-SERS substrate had good selectivity to PAT.Finally,using blueberry sauce,pomelo sauce and orange juice as the real samples,the accuracy and practicability of the MIPs-SERS substrate were confirmed.2.Preparation of surface-imprinted SiO2@Ag NPs SERS substrate based on the second-generation hotspots and its application for BPA detection in water samples.Using SiO2@Ag NPs as carrier,compared with monodisperse Ag NPs,the surface of the core-satellite like SiO2@Ag NPs loaded a lot of Ag NPs,which can produce more“hot spots”,to further enhance the activity of SERS effect.Then using TEOS as functional monomer,APTES as crosslinking agent,HRP as initiator and BPA as template molecule,after surface imprinting polymerization,the substrate which can specificly detect BPA was obtained.The MIPs-SERS substrate has a high sensitivity for the detection of BPA,the detection limit is 1.46×10?1111 mol/L?S/N=3?and the linear range of this substrate is1.75×10–9mol/L1.75×10–6mol/L.Specific experiments with BPA structure analogues for interferon showed that the MIPs-SERS substrate had good selectivity to BPA,the study of reproducibility and stability also achieved good results.Finally,using south lake water,tap water and pure milk as real samples,the accuracy and practicability of the MIPs-SERS substrate were confirmed. |
PDF Full Text Request