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Smart Agriculture ›› 2024, Vol. 6 ›› Issue (1): 76-88.doi: 10.12133/j.smartag.SA202311001

• 专题--智能农业传感器技术 • 上一篇    下一篇

油菜素内酯原位检测电化学免疫传感器

卫倩1,2(), 高原源1, 李爱学1,2()   

  1. 1. 江苏大学 农业工程学院,江苏 镇江 212000,中国
    2. 北京市农林科学院智能装备技术研究中心,北京 100097,中国

Electrochemical Immunosensor for in Situ Detection of Brassinolide

WEI Qian1,2(), GAO Yuanyuan1, LI Aixue1,2()   

  1. 1. College of Agricultural Engineering, Jiangsu University, Zhenjiang 212000, China
    2. Intelligent Equipment Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
  • Received:2023-10-26 Online:2024-01-30
  • corresponding author:
    LI Aixue, Ph.D., professor, research interest is agricultural engineering. E-mail:
  • About author:WEI Qian, research interest is agricultural engineering. E-mail:
  • Supported by:
    the National Key Research and Development Program of China(2022YFD2002301); the Beijing Natural Science Foundation(2222007); the Construction Project of Key Laboratory of Agricultural Sensors of Ministry of Agriculture and Rural Affairs(PT2023-46)

摘要:

目的/意义 植物激素的调控对于作物生长至关重要。油菜素内酯作为一种重要的植物内源激素,在作物的生长发育、产量提高以及抗逆性增强等方面扮演着举足轻重的角色。传统的油菜素内酯检测方法不仅繁琐耗时,而且难以实现原位、快速检测。为了突破这一技术瓶颈,本研究提出了一种利用丝网印刷(Screen-printed electrode, SPE)电极构建的电化学免疫传感器,旨在实现对油菜素内酯的快速、准确检测。 方法 首先利用电化学工作站电沉积金纳米颗粒(AuNPs)将其固定在SPE电极表面,然后在电极上滴加氯化铜纳米线(CuCl2 NWs),氯化铜纳米线不仅可以提高电极的导电性,其中Cu2+还可以作为传感器的氧化还原探针。最后选择Mxene和聚多巴胺纳米复合材料(Mxene@PDA)作为SPE电极的修饰材料,因为Mxene具有表面积大和导电性好的优点,可以进一步放大Cu2+的信号。但Mxene在空气中很容易被氧化而不稳定。聚多巴胺(Polydopamine, PDA)含有大量的邻苯二酚和氨基等基团,通过多巴胺自聚合后包覆在Mxene的表面,切断氧渗透的路径,使Mxene难以被氧化。Mxene@PDA还可以作为偶联剂在电极表面固定更多的抗体,提高整体的生物相容性。 结果和讨论 传感器具有较宽的线性检测范围:0.1 pg/ml~1 mg/ml,检出限低至0.015 pg/ml (S/N=3)。此外,通过SPE电极对小麦内源的油菜素内酯含量进行离体检测和后续的加标实验,计算出其回收率为98.13%~104.74%。在验证该传感器准确性的同时,也展示了其优越的稳定和灵敏性。与其他油菜素内酯的检测方法相比,本研究中开发的免疫传感器有更加出色的分析性能。除此之外,在对小麦叶片的油菜素内酯的原位检测中,传感器也表现出了极佳的实际应用潜力。 结论 本研究首次研制了用于原位检测油菜素内酯的电化学免疫传感器,不仅为原位检测植物叶片中的油菜素内酯提供了良好的电化学平台,同时在精准农业中具有巨大的应用潜力。

关键词: 油菜素内酯, 原位检测, 电化学, 金纳米颗粒, 免疫传感器

Abstract:

Objective Brassinolide is an important endogenous plant hormone. In this work, an electrochemical immunosensor for in situ detection of brassinolide was constructed using screen-printed electrode (SPE). Methods Au nanoparticles (AuNPs) were firstly electrodeposited on the surface of SPE electrode by electrochemical workstation, and then CuCl2 nanowires (CuCl2 NWs) were added to the electrode, which can not only increase the conductivity of the electrode, but also Cu2+ can be used as a REDOX probe for the sensor. Finally, Mxene and polydopamine nanocomposite (Mxene@PDA) were selected as the modification materials for SPE electrodes because Mxene has the advantages of large surface area and good electrical conductivity, which can further amplify Cu2+ signals. However, Mxene is easily oxidized and unstable in air. Polydopamine (PDA) contains a large number of catechol and amino groups, which are coated on the surface of Mxene after self-polymerization by dopamine, cutting off the path of oxygen penetration, making Mxene difficult to be oxidized. Mxene@PDA can also be used as a coupling agent to fix more antibodies on the electrode surface, improving the overall biocompatibility, and improve the overall biocompatibility. Results and Discussions The sensor has a wide linear detection range: 0.1 pg/mL to 1 mg/mL, and the detection limit was 0.015 pg/ml (S/N=3). In addition, the content of endogenous brassinolide in wheat was detected by SPE electrodes in vitro and the recovery rate was 98.13% to 104.74%.While verifying the accuracy of the sensor, it also demonstrated its superior stability and sensitivity. Besides, the sensor also showed excellent application potential in the in situ detection of brassinosteroids from wheat leaves. Compared with other brassinolide detection methods, the immunosensor developed in this study has better analytical performance. Conclusions An electrochemical immunosensor for in situ detection of brassinolide was developed for the first time, providing a good electrochemical platform for in situ determination of brassinolide in plant leaves, which has great application potential in precision agriculture.

Key words: brassinolide, in situ detection, electrochemical, AuNPs, immunosensor