Near‐Infrared Imaging of H 2 O 2 in Plants With Nanosensors Under Environmentally Changing Conditions

ABSTRACT Optical sensors are powerful tools to monitor biological systems. However, their practical deployment is often limited by environmental interferences such as autofluorescence, mechanical motion, and fluctuating illumination. These challenges are particularly pronounced in plants because they require and use light, which has impaired the use of (fluorescent) sensors for plant stress signals such as H 2 O 2 . Here, we present a ratiometric sensing platform that overcomes these limitations by integrating three spectrally distinct components: 1) an H 2 O 2 sensor based on aptamer modified near infrared (NIR) fluorescent single walled carbon nanotubes (SWCNTs, ∼1000 nm), 2) a stable NIR reference based on polyethyleneglycol modified Egyptian Blue nanosheets (EB–NS, 900–955 nm) and 3) a visible (VIS) signal (∼641 nm) to correct for the NIR autofluorescence tail of plants (>835 nm). This ratiometric approach enables robust signal correction under relevant perturbations, including leaf rotation and wind‐induced motion. Furthermore, it allows continuous H 2 O 2 monitoring under dynamically varying illumination conditions (>300%), resulting in a 75% enhancement in signal contrast compared to single‐channel detection. By spectrally resolving nanosensor signals and endogenous plant autofluorescence, this strategy enables in vivo monitoring of stress‐induced H 2 O 2 under realistic environmental conditions. It establishes interference‐resistant optical sensing and advances field‐deployable nanosensor technologies for precision agriculture.