Fabrication Of Fluorescent System And Its Application In The Detection Of Liquor Flavoring Substances

Chinese liquors contain 98%to 99%of water and ethanol,and 1%to 2%of different trace flavoring substances,mainly including,aldehyde,acid,ester and so on.Species and content of these flavoring substances play significant roles in the flavor and style of the Chinse liquor.Therefore,discrimination of these flavoring substances is of great importance in Chinese liquor industry.Optical sensor array stands out several advantages of wide spectrum response,high sensitivity,rich output signal in the detection of the mixtures.In this work,we presented a fluorescent sensor array to discriminate different types of Chinese liquors,by combining with mathematical statistics method,principal component analysis（PCA）and discriminant analysis（LDA）.The specific work islisted as following:（1）A simple and rapid IFE-based fluorescent sensor for the discrimination of aldehydes was fabricated.Strong extinction effect of KMnO₄ on excitation spectrum of GSH-CdTe leads to a significant fluorescence quenching.Mn（Ⅶ）could be turned into Mn（Ⅱ）,upon reaction with-CHO,which prevented the fluorescence quenching and therefore employed for aldehydes detection.GSH-CdTe were successfully synthesized through one-pot method and characterized using TEM and XPS.Formaldehyde served as model compound,optimal concentration of KMnO₄ and incubation time of KMnO₄and formaldehyde were investigated.Under the optimal conditions,a favorable linear relationship for formaldehyde detection was acquired ranged from 0 to 80μM,as well as a low detection limit of 9.33 nM（3S/N）.In addition,interference test suggested its potential capability of aldehydes differentiations and anti-disturbance ability for others.All these results demonstrate that the sensor system presented here could be a promising candidate in aldehydes discrimination.（2）Nitrogen doped graphene quantum dots（N-GQDs）,7-amino-4-methylcoumarin（AMC）,5,10,15,20-Tetrakis（4-hydroxyphenyl）porphyrin（THPP）and5,10,15,20-tetrakis（4-carboxylphen-yl）-porphyrin（TCPP）were synthesized and sever as sensing dots to form fluorescent array combined with GSH-CdTe for the discrimination of 9 aldehydes（Acetaldehyde,Acetal,2-Furaldehyde,Propanal,Isobutyraldehyde,Butyraldehyde,n-Pentanal,1-Pentanecarbaldehyde）.Effect of aldehydes with different concentrations（1μM,5μM and 10μM）on the fluorescent sensing dots was investigated using acetaldehyde as model,indicating the different fluorescence quenching of sensing dots.And discrimination of 3 aldehydes（Acetaldehyde,Acetal,and 2-Furfuraldelhyde）with different concentrations（1μM,5μM and 10μM）was successfully achieved without misclassification.Finally,9aldehydes above mentioned with concentration of 5μM and 10μM were differentiated based on the sensor array with satisfactory results.These observations indicate the sensor array displayed the potential capability of discriminating the Chinese liquors based on the aldehydes differentiations.（3）The presented sensor array was employed to discriminate 5 acids（acetic acid,propionic acid,butyric acid,lactic acid and lactic acid）and 5 esters（ethyl acetate,ethyl lactate,ethyl formate,ethyl hexanoate and ethyl butyrate）with concentration of 10μM.All of these acids and esters were clearly differentiated.Finally,8 baseliquors（CT,CH,CJ2,LX,CX,DZ2,ZL2 and JX）were selected as real samples to investigate the practicability of the presented sensor array.These results demonstrate that as-fabricated sensor array possessed a potential application in Chinese liquors industry discrimination.