高性能表面增强拉曼散射基底用于变压器油中糠醛的检测

Detection of Furfural Dissolved in Transformer Oil by High-Performance SERS Substrates

本文使用原位生长法制备了一种平面凹槽微腔阵列表面增强拉曼散射(SERS)基底,以4-氨基苯硫酚为探针分子,通过席夫碱缩合反应实现对变压器油中糠醛分子的捕捉,根据反应生成的碳氮双键在1658 cm-1处的特征拉曼谱带与糠醛浓度的关系,实现了变压器油中微量糠醛的定量检测。研究结果表明,该方法测定变压器油中糠醛的检出限约为0.05 mg/L,在0.1~100 mg/L糠醛浓度范围内,1658 cm^(-1)和1080 cm^(-1)处的峰强比值与糠醛浓度的对数具有良好的线性关系,所得线性回归方程为y=4.4156x+10.2612,相关系数R^(2)=0.9862。该方法采用商品化便携式拉曼光谱仪,为拉曼光谱应用于变压器油中微量糠醛的现场快速检测奠定了良好的基础。

In this paper,surface enhanced Raman scattering(SERS)substrates with microcavity arrays were designed by in situ growth method and prepared for furfural detection,where furfural was captured through the Schiff base reaction with p-mercaptoaniline on the surface of the substrate as the probe molecule.A characteristic Raman band peaked at 1658 cm-1,which originates from the newly formed C=N double bond and whose intensity can be correlated with furfural concentration,was selected to quantitatively detect trace furfural dissolved in transformer oil.The intensity ratio of the peaks at 1658 cm^(-1) and 1080 cm^(-1),I 1658/I 1080,shows a good linear relationship with the logarithm of furfural concentration within the range of 0.1-100 mg/L,with a detection limit of 0.05 mg/L.The linear regression equation is y=4.4156x+10.2612,and the coefficient of determination R^(2) is 0.9862.Furthermore,the proposed method was demonstrated with a commercialized portable Raman spectrometer rather than one designed for lab research,thus laid a solid foundation for rapid on-site detection.