Tracking Nanofertilizer (Au@mZnO-mSiO₂) Uptake and Transportation in Cucumber Simultaneously by LA-ICP-MS and ICP-MS

Enhancing the absorption efficiency of fertilizers plays an extremely crucial role in agricultural production. Here, we present a novel metallic nanofertilizer with a core-shell structure named Au@mZnO-mSiO₂ for the sustained release of Zn in plants. Detection with ICP-MS found that the content of Zn in the cucumber incubated with Au@mZnO-mSiO₂ exhibited a significantly higher content of Zn than the blank. The results of imaging with laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) showed significant increases in Zn, Cu, and P in cucumber leaves incubated with Au@mZnO-mSiO₂. The cucumber incubated with Au@mZnO-mSiO₂ had longer roots, thicker stems, and enlarged leaves, which indicated that Au@mZnO-mSiO₂ showed favorable effects on the growth of the cucumber. This work has meaningful implications for nanofertilizers in the advancement of sustainable agricultural production and also provides a novel tracking method for the study of nanoparticles in plant translocation pathways simultaneously, with their quantitation by ICP-MS and imaging by LA-ICP-MS.