A multiplexed wearable microfluidic platform for non-invasive sweat-inspired monitoring of plant guttation biomarkers

Plant guttation fluid provides a chemically informative readout of internal plant status, offering an externally accessible window into plant physiological processes. However, its minute volume, intermittent availability, and susceptibility to evaporation limit its use for continuous biochemical monitoring. Here we introduce PlantIonics, an integrated on-leaf microfluidic electrochemical platform for real-time, non-invasive monitoring of guttation biomarkers and leaf microenvironment. A bioinspired wedge-shaped microchannel with asymmetric wettability achieves rapid (0.6 s) and unidirectional self-driven fluid collection, providing a continuously refreshed sensing interface for dynamic guttation profiling. Combined with a multichannel sensor array and a compact wireless flexible printed circuit board, PlantIonics simultaneously measures guttation-fluid biomarkers (potassium, sodium, glucose) and local leaf microenvironment. Multi-day on-plant studies demonstrate stress-responsive guttation fluctuations that correlate with root-level ionic perturbations and light modulation, demonstrating the platform’s capability to monitor dynamic physiological regulation. PlantIonics establishes a sweat-inspired analytical framework for non-invasive plant monitoring, offering opportunities for early stress diagnostics, field phenotyping, and precision agriculture. Plant sensors are emerging as key tools for precision agriculture, yet continuous monitoring of biomarkers in plant biofluids remains underdeveloped. Here, the authors introduce PlantIonics, a wearable microfluidic electrochemical platform for multiplexed, in situ analysis of guttation fluid. The system enables continuous, noninvasive monitoring of stress-associated plant physiological and metabolic responses under changing environmental conditions.