Study On The Construction And Detection Performance Of Colorimetric Sensor Arrays For The Distinction Of Aldehydes

As one of the most common sources of pollution,aldehydes are widely found in people’s daily life,which seriously endangers the ecological environment and physical health.At the same time,they are also flavor substances of food,which are closely related to food safety.Therefore,it has important research value and social significance for the identification and detection of aldehydes.The visual sensing array with cross-response properties can be used as an effective way for aldehyde detection and quantitative analysis,because of its advantages of simple operation,low cost,convenient,efficient,fast response speed,and visual results.Therefore,this paper constructs a specific visual sensing system for the identification and quantitative detection of aldehydes.The main research contents are as follows:(1)Identification and detection of aldehydes by visual sensing system based on Cannizzaro reaction.In this sensor,OH~-was used as nucleophilic reagent to react with aldehyde and phenol red as indicator to show its color change.The liquid sensing system that can be observed through naked eyes was constructed.The visualization recognition of 7aldehydes and acetic acid was achieved under the optimum reaction conditions,with specificity and accuracy greater than 87.5%.The acetaldehyde concentration has a good linear relationship in the concentration range of 0.1 m M～10 m M,and the lowest theoretical detection limit is 0.08 m M,indicating that this colorimetric sensing system has the potential to quantitatively detect aldehydes.(2)Quantum dot-based visual sensing system for identification and detection of aldehydeBased on the difference in the quenching of fluorescence between the reaction between different aldehydes and ligands of Cd Te QDs,we successfully constructed a color sensor array to discriminate aldehydes,including Cys-Cd Te QDs,GSH-Cd Te QDs and TGA-Cd Te QDs.Under optimal conditions,the array achieves accurate classification of eight aldehydes at low concentrations.Its recognition accuracy and specificity are greater than 85.7%.The concentration of formaldehyde is in the range of0.1 m M～50 m M.There is a good linear relationship between the total Euclidean distance of the array and the logarithm of the formaldehyde concentration(R~2=0.9937),and the minimum detection limit is 0.07 m M.Based on the above result,we have demonstrated the colorimetric array ability in quantitative determination of formaldehyde.(3)Detection of aldehydes by colorimetric sensing array of gold nanoparticles based on Tollens’reagentBecause of the redox reaction between Tollens’reagent and aldehydes,the silver monomer produced by reaction adsorb at the surface of gold nanoparticles,forming a"silver wrapped gold"core-shell structure,while the color changes.A gold nanoparticles colorimetric sensing array was constructed to distinguish and identify ten aldehydes,as well as quantitative detection of formaldehyde.The excellent selectivity and repeatability of the array were confirmed by relevant experiments.Except benzaldehyde,the recognition accuracy was over 95%.Except benzaldehyde,the specificity reached100%.Under optimum conditions,the gold nanoparticles array achieves accurate and rapid classification of ten aldehydes at low concentrations.There is a good linear relationship between formaldehyde concentrations in the range of 0.1～10000 m M,and when shrimp is used as real sample,there is a good standard-added recovery rate of85.8%～114.82%,which indicates that the array has a good detection effect on aldehydes.