| Raman scattering phenomenon was an inelastic scattering spectrum which was observed by Indian physicist Raman in experiment.The general Raman spectrum was very weak intensity so it had great limitations in practical applications.The appearance of surface-enhanced Raman spectroscopy?SERS?broaded its application.It could increase the Raman signal by 5 to 8 orders of magnitude and it was not interfered by impurities such as solvents.Simultaneously,It had a high degree of accuracy.In addition,SERS also had the advantages of high sensitivity,providing characteristic fingerprint peaks,non-destructive testing,etc.Nowadays,SERS technology has been widely used in biomedical,environmental monitoring,material analysis,archaeology and many other fields.With the development of science and technology,the application value and field of SERS will continue to expand.This article mainly studies the application of SERS technology in food and drug analysis.We had prepared a new type of film-like gold nanostructures as a reinforcing substrate for SERS,optimizing the preparation conditions and making the prepared substrate more efficient and stable.Based on this newly prepared gold nanoparticle,the interaction between two kinds of analgesic drugs and BSA was studied using SERS technology,which Provided a new way to study the interaction between substances.Then using SERS to detect chlortetracycline residues in honey.Establishing a new and efficient method for the detection of drug residues in food.That Providing a new idea and method for food and drug testing.The main contents are as follows:Chapter One:introduce the background,development and characteristics of Raman spectroscopy and surface-enhanced Raman spectroscopy.The principle of SERS was descriped by the combination of graphics and the research progress and application areas of SERS were also introduced.Chapter Two:a simple and efficient method was developed to prepare a new membrane-like nanoparticles substrate.PVP was used as protectant and binder and gold nanoparticles was perpared by chemical reduction method.The effects of the reaction conditions on the reaction were investigated,include species of reducing agent,the temperature of the reaction,pH of the reaction system and the concentration of reducing agent.A new membrane-like nanoparticles substrate which had the best enhanced effect was perpared.The SERS characteristic of the substrate was inspected by rhodamine B.Its enhancement factor could reach to 6.5×105.The shape of gold nanoparticles was characterized by SEM.The results showed that it has a membrane structure and a large specific surface area which is conducive to molecular absorption.Compared with the traditional precious metal nanoparticles substrate,the new membrane-like gold nanoparticles substrate had a better enhanced effect and higher detection senstivity and accuracy.All in all,it has a wide application prospect.Chapter Three:two kinds of analgesic drugs,nabumetone and tetrahydropalmatine,and BSA were characterized by SERS.The positions of the characteristic peaks in their molecules were assigned.The principle and the way of combining betweent them and gold nanoparticles were studied.The result showed that the main factor of enhancement was the electron interaction between?electron cloud coexisting in them and the gold nanometer to generate the electromagnetic effect and enhance the intensity of the peak.Simultaneously,it was proved that the Raman enhancement effect was best when gold nanoparticles and nabumetone and tetrahydropalmatine were mixed in a ratio of 1:2.In addition,the SERS spectra of the two samples were collected at different pH conditions,which showed that both were stable in both acidic and basic conditions.By comparing the SERS spectra of nabumetone and tetrahydropalmatine in the presence or absence of BSA,we found that most of the characteristic peaks of both were unchanged with only a few changes,demonstrating that in the action with BSA.The molecular structure of nabumetone and tetrahydropalmatine is relatively stable,and the Raman intensity were further enhanced after the action.This method provided a new way to study the analgesic drugs and their interaction with proteins,which is also an efficient,non-destructive and convenient method for the analysis and detection.This new method deserved to be researched and popularized in more fields.Chapter Four:A new detection method using surface enhanced Raman spectroscope?SERS?was established for rapid and nondestructive detection of chlortetracycline?CTC?in honey.Gold nanoparticle,prepared by ourselves,was used as Raman signal enhancement module.The influence of volume ratio and interact time between gold nanoparticle and CTC was discussed and optimized.Different concentration of CTC solution were detected.The linear equation of concentration and Raman signal strength on characteristic peak was drawing.After pretreated,the recovery rate of honey sample was detected by the recovery of standard addition.The characteristic peak of chlortetracycline in 1450 cm-1 could be used to detecting chlortetracycline?CTC?residues in honey.The best volume ratio of gold nanoparticle and CTC was 1:1 and the best interact time was 1 min.Within the scope of 10250mg/L,there was a favorable linearity between the concentration of CTC and SERS characteristic peak in 1450 cm-1.Linear equation was Y=1×10-4X+0.0110,and the coefficient of determination was 0.9948.Recovery rate was from 80%to 120%when detecting chlortetracycline?CTC?residues in honey.Simply,quickly and highly accuracy,this method could be used to rapid and nondestructive detection of chlortetracycline?CTC?in honey. |
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