Carbon dot based sensing platform for real-time imaging Cu²⁺ distribution in plants and environment

Divalent copper is a double-edged sword for plants, excess or shortage of copper ions will cause adverse reactions in plants. Currently, Cu²⁺ sensor for plants is still underdeveloped and new technology is urgently required for realizing one-step and real-time detection of Cu²⁺ in plants. Herein, a home-made and low-cost sensing platform is constructed by using carbon dots (CDs) as the optical probe, electronic devices for image acquisition, and a built-in algorithm program for image processing, which allows the dynamic monitoring of Cu²⁺ distribution in different plant species with high spatial and temporal resolution. We found that the detection limit of R-CDs for Cu²⁺ in water sample was 0.375 nM, and 11.7 mg/kg or even less Cu²⁺ in plants can be visually observed and accurately detected by the sensing platform. Moreover, this sensing platform has also been employed for reporting the spatial distribution of Cu²⁺ in the external environment of plants, demonstrating its applicability for monitoring Cu²⁺ both in living plants and the surrounding environment. This study provides a smart sensing platform for precise detection in plant internal and external environments, offering a promising strategy for precision agriculture in real-time and remote-control manners.