MIP-SERS技术快速检测中药中非法添加的茶碱

摘要

建立了分子印迹技术(MIP)与表面增强拉曼光谱(SERS)联用对中药中非法添加的茶碱成分快速检测的方法.基于沉淀聚合方法合成MIP微球,对复杂中药基质中的茶碱进行简单分离,采用SERS对MIP中吸附的茶碱进行定性检测.实验利用SEM,FT-IR对MIP结构表征,考察了MIP的热力学、动力学和选择性吸附能力,以及掺杂成分的检出限.结果表明,MIP比NIP对茶碱具有更好的特异性吸附和选择性,该方法对茶碱的检出限低至0.1 μg/L.方法用于5种止咳平喘类中药的检测,其中1种中药检出非法添加了茶碱成分.该法灵敏度高,特异性强,无需前处理,简单快速,实现了掺伪中药中茶碱的快速检测,有望进一步应用于其他复杂基质体系.%A rapid method combining molecularly imprinted polymers with surface-enhanced Raman spectroscopy (MIPs-SERS) was established for the determination of theophyline illegally added into traditional Chinese Medicine.MIPs were synthesized by precipitation polymerization,and the theophylline was simply separated from the complex traditional Chinese medicine(TCM) substrates,then detected qualitatively by SERS.The structures of the newly synthesized MIPs were characterized by Fourier transmission infrared spectrometry (FT-IR) and scanning electron microscopy (SEM).The thermodynamics and kinetics and selective adsorption capacity of the MIPs,as well as the limit of detection for adulteration were also investigated.The results showed that MIPs had a better specificity and selectivity than NIPs,and the limit of detection was as low as 1 μg/L.Five kinds of real TCM relieving cough and asthma were tested,and one sample was detected to have theophylline components added illegally.With the advantages of high sensitivity,strong specificity,no pretreatment,simplicity and rapidness,the method could be used for the rapid detection of theophylline illegally added in TCM and further applied in other complicated matrix system.