Analytical & Testing Centre, Sichuan University, Chengdu, Sichuan, 610064, China.
State Grid Sichuan Electric Power Research Institute, Chengdu, Sichuan, 610041, China.
Talanta. 2022 Jan 15;237:122925. doi: 10.1016/j.talanta.2021.122925. Epub 2021 Oct 6.
Herein, a facile and fast surface-enhanced Raman scattering (SERS) method with ratiometric strategy was developed for detection of 4-methylimidazole (4-MI). Via a chemical derivatization reaction with 3-amino-5-mercapto-1,2,4-triazole (AMTA) diazonium salts, 4-MI could be converted to SERS-sensitive species. The SERS intensity ratio between the peaks at 1243 cm and 1110 cm (I/I) was used for the quantification of 4-MI. In addition, the method sensitivity was further improved by the aggregation of beta-cyclodextrin-modified Ag nanoparticles (beta-CD-AgNPs). Under the optimal conditions, the limit of detection (LOD) and the limit of quantification (LOQ) for 4-MI were 1.7 nM (S/N = 3) and 5.7 nM (S/N = 10), respectively. The relative standard deviation (RSD) for 0.5 μM 4-MI was 8.2% (n = 20). This method was successfully used for the determination of 4-MI in cola samples with recoveries ranging from 92% to 106%. The present method is convenient, sensitive, selective, reliable and may have a promising application in determination of the compounds with an imidazole ring containing active hydrogen atoms.
本文开发了一种简便快速的表面增强拉曼散射（SERS）比率法，用于检测 4-甲基咪唑（4-MI）。通过与 3-氨基-5-巯基-1,2,4-三唑（AMTA）重氮盐的化学衍生化反应，4-MI 可转化为 SERS 敏感物质。1243 cm 和 1110 cm 峰的 SERS 强度比（I/I）用于定量 4-MI。此外，通过β-环糊精修饰的 Ag 纳米粒子（β-CD-AgNPs）的聚集进一步提高了方法的灵敏度。在最佳条件下，4-MI 的检测限（LOD）和定量限（LOQ）分别为 1.7 nM（S/N = 3）和 5.7 nM（S/N = 10）。对于 0.5 μM 4-MI，相对标准偏差（RSD）为 8.2%（n = 20）。该方法成功用于可乐样品中 4-MI 的测定，回收率在 92%至 106%之间。本方法简便、灵敏、选择性好、可靠，可能在测定含活泼氢原子的咪唑环化合物方面有很好的应用前景。
