<p>Ion-selective electrodes (ISEs) are pivotal tools for real-time, non-destructive monitoring of ionic dynamics in living plants, addressing key challenges in agriculture, plant physiology, and environmental science. This review presents recent advancements in ISE-based in vivo detection technologies, with an emphasis on sensor architectures tailored for plant tissues, including screen-printed planar electrodes, flexible electrodes, microneedle electrodes, and microfluidic devices. These systems enable precise in situ quantification of essential ions and trace elements, providing valuable insights into fundamental physiological processes such as nutrient uptake, stress responses, and signal transduction. Building on current ISE fabrication techniques, the review is aimed at developing a more cohesive theoretical framework for their application in plant systems. Future directions focus on synergistic integration of wearable plant sensors to build comprehensive real-time monitoring systems, which could advance understanding of plant–environment interactions and help address global food security challenges.</p> Graphical Abstract <p></p>