Assessment of Salt Stress to Arabidopsis Based on the Detection of Hydrogen Peroxide Released by Leaves Using an Electrochemical Sensor

Salt stress will have a serious inhibitory effect on various metabolic processes of plant cells, this will lead to the excessive accumulation of reactive oxygen species (ROS). Hydrogen peroxide (H2O2) is a type of ROS that can severely damage plant cells in large amounts. Existing methods for assessing the content of H2O2 released from leaves under salt stress will cause irreversible damage to plant leaves and are unable to detect H2O2 production in real time. In this study, on the strength of a series of physiological indicators to verify the occurrence of salt stress, an electrochemical sensor for the detection of H2O2 released from leaves under salt stress was constructed. The sensor was prepared by using multi-walled carbon nanotube-titanium carbide-palladium (MWCNT-Ti3C2Tx-Pd) nanocomposite as substrate material and showed a linear response to H2O2 detection in the range 0.05-18 mM with a detection limit of 3.83 μM. Moreover, we measured the determination of H2O2 released from Arabidopsis leaves at different times of salt stress by the sensor, which was consistent with conventional method. This study demonstrates that electrochemical sensing is a desirable technology for the dynamic determination of H2O2 released by leaves and the assessment of salt stress to plants.