| Surface-enhanced Raman Spectroscopy?SERS?is a spectroscopic technology with significant enhancement of Raman scattering signals.The Raman enhancement effect would occur when target molecules are absorbed on substrate or modified substrate surface.It can provide“fingerprint”information of molecules,which is a powerful tool for qualitative or quantitative detection of chemicals.It has many advantages of low requirement of sample,little background interference of water,fluorescence and phosphorescence,simple operation,high sensitivity and short time,which makes SERS widely used in many fields such as life science,food safety,medical and health.In view of advantages,we applied it to the research and detection of drug and food additives.In this paper,we have explored the analgesic mechanism of the non-steroidal indomethacin?IMC?.Furthermore,SERS is used to detect sodium saccharin in dried fruit foods,aspartame?APM?in soft drinks,as well as Acesulfame-K in candy.The main contents of this paper are as follows:?1?In this paper,we expounded the development history,fundamental principles and characteristics of Raman spectroscopy and SERS,and summol/Larized the progress of SERS in some research fields.?2?Silver as a heavy metal,can destroy the structure of protein.For that reason,we used L-cysteine?L-Cys?modified silver nanowires as substrate to investigate the spectral behavior of the interaction between IMC and protein in solution with pH 5.0,7.0 and 9.0.With the help of spectrogram,we infered that IMC may enter the hydrophobic cavity of protein in three chemical environments and form molecular associations,which lead to the destruction of hydrophobic channels,hinderd the entry of some chemicals and inhibited the synthesis of related enzymes.Although it relieved pain,it also caused side effects.?3?Detection of sodium saccharin in dried fruits using SERS.According to classify Raman peaks of saccharin sodium,the characteristic peak of 707 cm-11 was determined as the basis.In order to determine the feasibility of the experimental method,we optimized the experimental conditions,and discussed the selectivity and stability of characteristic peaks.Under the optimum experimental conditions,a good linear relationship was demonstrated between SERS peak intensity and mass concentration in the range of 0.5-100.0 mg/L,and the result indicated that the minimum detection limit of saccharin sodium is about 0.48 mg/L.Due to its simple,fast,strong specificity and high sensitivity,it has been detected saccharin sodium in plum,raisins,melon seeds and peanuts.The results showed that the recoveries ranged from 99.9%to114.7%,and the relative standard deviation was less than 9.0%.?4?In this paper,SERS was applied to analyse the APM in soft drinks.Based on the enhancement effect of silver nanoparticles,we analyzed the SERS spectra of APM standard solution and four kinds of soft drinks to determine the quantitative basis.Under the experimental conditions of pH 5.0,silver nanoparticles to APM volume ratio1:1,mixing temperature 30?,heating time 6 minutes,we established a standard curve of peak intensity corresponding to mass concentration of 1001 cm-1.A good linear regression was found between Raman peak at 1001 cm-11 and APM concentration ranged from 0.5 mg/L to 100.0 mg/L with a good determination coefficient of 0.9933.The recoveries of APM in soft drinks were 88.4%-120.8%,and the relative standard deviation was less than 7.0%.?5?Rapid detection of Acesulfame-K in candy by SERS.By using silver nanowires as the active substrate to occur enhancement,we optimized the pH,temperature and mixing ratio of the experimental system,and discussed the effect of additives on sensitivity.The linear SERS responsed from 0.5 mg/L to 100.0 mg/L of Acesulfame-K was established.The linear equation is Y=83.95 X+314.7,and a good liner coefficient is 0.9944.The results showed that the recoveries of Acesulfame-K were 91.2%-105.7%,and the relative standard deviation was between 4.3%and 6.1%in this study. |
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