Research And Application Of Nitrite Nanosensor Based On Functionalized Gold Nanoparticles

Nitrite is a common food additive used primarily for preservation and coloration.Nitrite is also a highly toxic substance.In recent years,food safety problems related to nitrite have occurred.However,the detection method of nitrite is not complete enough.Therefore,based on the traditional colorimetric method,this topic will be The p-aminothiophenol and naphthylethylenediamine salts were respectively modified onto gold nanoparticles,and the gold nanoparticles were aggregated by the coupling reaction with NO₂^-diazotization to change the optical properties and change the degree with NO₂^-.The concentration is positively correlated to achieve the purpose of detecting NO₂^-.Compared with the traditional colorimetric method,the new detection method has more obvious color development,can be used for naked eye detection,and has a lower detection line,and is suitable for rapid detection of trace nitrite in food.Taking sodium nitrite as the research object,this study established three detection methods based on different preparation methods of gold nanoparticles:p-aminothiophenol modified to aqueous gold nanoparticles,naphthylethylenediamine reaction to glutathione Peptide functionalized gold nanoparticles constitute the first detection method.Standard curve:y=0.7186x+0.0038,R₂=0.9992;p-aminothiophenol modified to aqueous phase gold nanoparticles,naphthylethylenediamine reaction is attached to mercaptopropionic acid functionalized gold nanoparticles to form a second detection method.Standard curve:y=0.767x+0.0029,R₂=0.9978;p-aminothiophenol modified to aqueous phase gold nanoparticles,naphthylethylenediamine reacted to coated oil phase gold nanoparticles to form a third test method.Standard curve:y=0.4634x+0.0403,R₂=0.995.The detection limits of the three detection methods were 3.06 ng/mL,4.82 ng/mL,and 10.14 ng/mL,respectively.The recoveries were 94.96-102.76%,94.42-103.29%,and 93.09-104.75%,respectively.The relative standard deviations were 3.76%,3.81%,4.60%.The three detection methods have good accuracy,stability and anti-interference ability.The nitrite content of pickled cabbage was tracked for 30 days by three detection methods.It was found that the content of nitrite in the cabbage was increased first and then decreased,reaching a maximum of 200?g/g after 10 days.Gradually,the nitrite content decreased to 18?g/mL on day 23 to meet national standards.A sample survey of some snack shops around the school found that about 50%of the merchants had food safety problems with excessive nitrite,and there were cases where nitrite exceeded the standard.