LEAF-MOUNTED MICRONEEDLE-BASED MULTISENSORY PLATFORM FOR MULTIPLEXED MONITORING OF PHYTOHORMONES IN LIVE PLANTS

Abstract

This paper presents a first-of-its-kind leaf-mounted microneedle-based multisensory platform for in situ monitoring of salicylic acid and indole-3-acetic acid in the leaves of a live plant. The multiplexed system has a built-in temperature sensor for temperature correction. The sensor could accurately detect salicylic acid and indole-3-acetic acid levels with detection limits of 1μM and 0.10μM, respectively. The measured hormone levels were corrected based on the variations in leaf temperature in an actual field condition. Since phytohormone signaling is a plant's first response to environmental stresses, early identification of these stress hormones will help growers to implement site-specific interventions and mitigate productivity losses. Moreover, our continuous and in situ sensor will advance future research on improving plant growth in space missions (NASA Space Biology's research priority).