Tao Pan, Luo Yang, Zheng Kai, Cao Jing, Zhu Li, Wang Xunsi, Zhang Wei, Dai Shixun, Zou Qiushun, Zhang Peiqing
Zhejiang Key Laboratory of Advanced Optical Functional Materials and Devices, Ningbo University, Ningbo, 315211, China; Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province, Ningbo University, Ningbo, 315211, China; Department of Optical Engineering, School of Electronic Science and Engineering, Southeast University, Nanjing, 211189, China.
Zhejiang Key Laboratory of Advanced Optical Functional Materials and Devices, Ningbo University, Ningbo, 315211, China; Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province, Ningbo University, Ningbo, 315211, China.
Anal Chim Acta. 2025 Mar 1;1341:343646. doi: 10.1016/j.aca.2025.343646. Epub 2025 Jan 10.
Permethrin is a pesticide used to kill insects, and once used in excess, it poses a great threat to the environment and human health, therefore, it is necessary to realize the rapid and accurate detection of permethrin. Fiber optic surface enhanced Raman scattering (SERS) probes have the advantages of small volume and can be used for remote monitoring, which have great potential for application in achieving in-situ detection of pesticide residues.
Fiber taper waist (FTW) SERS probes modified by silver nanocubes-graphene oxide (Ag NCs-GO) composite structures were prepared for in situ detection of permethrin in lake water. Evanescent wave was used to excite SERS signals from Ag NCs-GO composite substrates, which was designed to enhance signals through expanded excitation light-analyte contact area. Ag NCs can provide stronger hot spots, and GO further enhances the sensitivity of SERS through electron transfer and improves the stability of the detection. The detection limit of prepared FTW SERS probe for Rhodamine 6G (R6G) was calculated to be 8.5 × 10 M and RSD were all below 5 % using the drop-casting method. The in-situ detection limit of R6G and permethrin in water was tested to be 10 M and 10 M, respectively.
This work utilizes fiber optic evanescent waves to excite SERS signals, and adopts a special FTW structure and SERS substrates to achieve good performance. The synergistic enhancement of electromagnetism and chemistry is realized while increasing the contact area, which improves the sensitivity of in situ detection of the pesticide residue permethrin. It Promotes the application of fiber optic SERS sensors in pesticide residue detection.
氯菊酯是一种用于杀灭昆虫的杀虫剂，一旦过量使用，会对环境和人类健康构成巨大威胁，因此，有必要实现对氯菊酯的快速准确检测。光纤表面增强拉曼散射（SERS）探针具有体积小、可用于远程监测的优点，在实现农药残留原位检测方面具有巨大的应用潜力。
制备了银纳米立方体-氧化石墨烯（Ag NCs-GO）复合结构修饰的光纤锥腰（FTW）SERS探针，用于原位检测湖水中的氯菊酯。利用倏逝波激发Ag NCs-GO复合基底的SERS信号，通过扩大激发光与分析物的接触面积来增强信号。Ag NCs可提供更强的热点，GO通过电子转移进一步提高SERS的灵敏度并改善检测的稳定性。采用滴铸法计算得到制备的FTW SERS探针对罗丹明6G（R6G）的检测限为8.5×10⁻⁸ M，相对标准偏差均低于5%。测试得到水中R6G和氯菊酯的原位检测限分别为10⁻⁷ M和10⁻⁷ M。
本工作利用光纤倏逝波激发SERS信号，采用特殊的FTW结构和SERS基底，性能良好。在增加接触面积的同时实现了电磁和化学的协同增强，提高了农药残留氯菊酯原位检测的灵敏度。推动了光纤SERS传感器在农药残留检测中的应用。
