Highly Sensitive and Selective Turn-On Fluorescent Carbon Dots for Real-Time Ethylene Sensing and Imaging in Plant Tissues

Ethylene is a volatile and low-reactivity plant hormone that is indispensable for regulating plant growth and fruit ripening. However, real-time and highly sensitive detection of ethylene in plants remains a significant challenge. Herein, we developed orange-emitting carbon dots (e-CDs) through solvothermal synthesis, integrating Grubbs catalyst-mediated olefin metathesis with the inherent adsorption properties of carbon dots to specifically recognize and turn-on response to a nonpolar ethylene molecule. By employing this innovative design, our fluorescent probe achieves a detection limit of 0.12 ppm and delivers a rapid (within 3 min), highly selective response in complex biological matrices. Utilizing these capabilities, we monitored endogenous ethylene release during fruit ripening and achieved spatially resolved fluorescence imaging of ethylene in both fruits and <i>Arabidopsis</i> leaves. This versatile sensor platform not only surpasses the sensitivity of previously reported small-molecule sensors but also broadens the applicability of carbon dots to nonpolar gas detection, providing a powerful new tool for advancing agricultural practices, food preservation, and fundamental plant physiology research.