Real-Time Subcellular Imaging of Plant Signaling Molecules and Bio-Coronas by Near-Infrared Nanosensors

Chemical imaging at high spatiotemporal resolution is crucial for advancing plant sciences and biotechnology. We demonstrate optical nanosensors for subcellular imaging of signaling molecules (H2O2) and lipid corona formation in plant tissues at high spatial (<1 μm) and temporal resolution (1 s) in the tissue transparent near-infrared (nIR) window. Nanosensor fluorescence peak quenching (12–25%) over time revealed the rapid propagation (<30 s) of exogenous H2O2 waves (100 μM) from plant mesophyll to stomata and pavement cells. Ca2+ induced higher endogenous H2O2 in mesophyll cells, whereas organelle electron transport chain disruptors and salt stress generated similar H2O2 across all leaf cell types. Furthermore, the nanosensor quenching kinetics in photosynthetic mesophyll (0.018 s–1) and epidermal (0.004 s–1) cells enabled the detection of plant lipid corona formation. Optical nanosensors elucidate spatiotemporal dynamics of plant signaling molecules and advance our understanding of biocorona formation.