Microneedle electrochemical sensor based on disposable stainless-steel wire for real-time analysis of indole-3-acetic acid and salicylic acid in tomato leaves infected by Pst DC3000 in situ

• Published in: Analytica chimica acta Vol. 1316; p. 342875
• Main Authors: Tang, Lingjuan, Li, Daodong, Liu, Wei, Tang, Yihui, Zhang, Rongcheng, Tian, Yiran, Tan, Rong, Yang, Xiaolong, Sun, Lijun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 08.08.2024
• Subjects: Disposable stainless steel wire; Electrochemical Techniques - instrumentation; Indole-3-acetic acid; Indoleacetic Acids - analysis; Microneedle electrochemical sensor; Needles; Plant Diseases - microbiology; Plant Leaves - chemistry; Plant Leaves - metabolism; Real-time and in situ electrochemical detection; Salicylic acid; Salicylic Acid - analysis; Solanum lycopersicum - chemistry; Stainless Steel - chemistry; Salicylic acid; Indole-3-acetic acid; Microneedle electrochemical sensor; Disposable stainless steel wire; Real-time and in situ electrochemical detection
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2024.342875

Indole-3-acetic acid (IAA) and salicylic acid (SA), pivotal regulators in plant growth, are integral to a variety of plant physiological activities. The ongoing and simultaneous monitoring of these hormones in vivo enhances our comprehension of their interactive and regulatory roles. Traditional detection methods, such as liquid chromatography-mass spectrometry, cannot obtain precise and immediate information on IAA and SA due to the complexity of sample processing. In contrast, the electrochemical detection method offers high sensitivity, rapid response times, and compactness, making it well-suited for in vivo or real-time detection applications. A microneedle electrochemical sensor system crafted from disposable stainless steel (SS) wire was specifically designed for the real-time assessment of IAA and SA in plant in situ. This sensor system included a SS wire (100 μm diameter) coated with carbon cement and multi-walled carbon nanotubes, a plain platinum wire (100 μm diameter), and an Ag/AgCl wire (100 μm diameter). Differential pulse voltammetry and amperometry were adopted for detecting SA and IAA within the range of 0.1–20 μM, respectively. This sensor was applied to track IAA and SA fluctuations in tomato leaves during PstDC3000 infection, offering continuous data. Observations indicated an uptick in SA levels following infection, while IAA production was suppressed. The newly developed disposable SS wire-based microneedle electrochemical sensor system is economical, suitable for mass production, and inflicts minimal damage during the monitoring of SA and IAA in plant tissues. This disposable microneedle electrochemical sensor facilitates in vivo detection of IAA and SA in smaller plant tissues and allows for long-time monitoring of their concentrations, which not only propels research into the regulatory and interaction mechanisms of IAA and SA but also furnishes essential tools for advancing precision agriculture. [Display omitted] •The microneedle electrochemical sensor system based on disposable stainless-steel wire were developed.•The microneedle electrochemical sensor system can realize the monitoring of SA and IAA in plants in situ and real-time.•The microneedle electrochemical sensor system can reduce the damage to plants during the detection of SA and IAA.•Our strategy will help to pave the foundation for further investigation of the regulation and crosstalk of SA and IAA in plants.