A novel ratiometric fluorescent probe for sensitive detection of jasmonic acid in crops

Herein, a novel ratiometric fluorescent probe was proposed for sensitive detection of jasmonic acid (JA) based on NCQDs@Co-MOFs@MIPs. The prepared NCQDs, with uniquely dual-emissive performance, are insensitive to JA due to electrostatic repulsion. Interestingly, the introduction of Co-MOFs not only avoided the self-aggregation of NCQDs, but changed the surface charge of NCQDs and triggered the response of NCQDs to JA. More importantly, the imprinted recognition sites from MIPs provided key-lock structures to specifically capture JA molecules, greatly improving the selectivity of the probe to JA. Under the synergistic actions of Co-MOFs and MIPs, JA can interact with NCQDs through photo-induced electron transfer (PET), resulting in the changes on emission in-tensity of the probe at Em = 367 nm and 442 nm. Based on the observations, the quantification of JA was realized in the range of 1-800 ng/mL with the limit of detection (LOD) of 0.35 ng/mL. In addition, the probe was used for detecting JA in rice with satisfactory analysis results, indicating the probe holds great potential for monitoring JA levels in crops. Overall, this strategy provides new insights into the construction of practical probes for sensitive detection of plant hormones in crops.

Automated summary

In this study, a novel ratiometric fluorescent probe was developed for sensitive detection of jasmonic acid (JA) using NCQDs@Co-MOFs@MIPs. The probe exhibited dual-emissive performance due to the introduction of Co-MOFs, which prevented the self-aggregation of NCQDs and changed their surface charge. The imprinted recognition sites from MIPs improved the selectivity of the probe by specifically capturing JA molecules. The probe successfully quantified JA in the range of 1-800 ng/mL with a LOD of 0.35 ng/mL and showed potential for monitoring JA levels in crops.