An in Vivo Surface-Enhanced Raman Scattering Nanosensor for Detecting Hydrogen Peroxide in Plants under Abiotic Stresses

Determining whether plants are under stress before obvious disease symptoms is crucial for precision agriculture. Intercellular hydrogen peroxide (H2O2) in plants can be used to indicate stress. However, most current H2O2 detection methods are destructive or limited by chlorophyllous autofluorescence. Herein, we constructed an in vivo surface-enhanced Raman scattering (SERS) sensor for nondestructive, in situ, and highly sensitive detection of H2O2 in plant leaves. The sensor with the designed size can enable nondestructive and in situ H2O2 detection without fluorescence interference. In addition, Ag decahedral nanoparticles with sharp edges and tips enhance the SERS effect, and the lowest detection concentration of H2O2 can reach 10 nM in vitro. The utility of the SERS sensor is demonstrated by Oxalis corniculata under wound, heat, and cold stresses. This SERS sensor can provide warnings before plants show visible signs of damage, thereby improving crop yields and potentially becoming an essential tool for precision agriculture.