In vivo tracking of leaf-delivered titanium dioxide nanopesticide in ginseng plant using surface-enhanced Raman scattering-labeled techniques

Nanotechnology integration into agricultural science and technology has led to the development of nano-pesticides, which are pivotal in enhancing the efficacy of pest control and reducing the environmental footprint of traditional pesticides. However, there is a significant knowledge gap regarding the absorption, transportation, and distribution of nanoparticle carriers within crops, which is essential for the safe and effective application of these nano-pesticides. Taking advantage of high sensitivity and minimal interference from biological backgrounds, herein, surface-enhanced Raman scattering (SERS) labeling technology was applied to track the in vivo distribution of nano-pesticide carriers in plant. AuNS@Cy7@TiO 2 model NPs with distinct near-infrared SERS signals were synthesized applied to ginseng leaves to monitor their behavior. SERS imaging results demonstrate that these NPs can migrate from treated leaflets to adjacent leaflets and petioles, penetrating the mesophyll tissue and distributing uniformly. Importantly, the absence of SERS signals in the aerial stem indicates that the NPs do not translocate to the roots, thus posing minimal risk to the medicinal parts of ginseng. The presence of the surfactant Silwet L-77 increases the migration distance of nanoparticles within the leaves. This study highlights the potential of SERS labeling for tracking NP movement in plants, providing insights into the absorption and transport mechanisms of nanocarriers, and guiding the development of safer and more effective nano-pesticides.