Rapid and In-Field Sensing of Hydrogen Peroxide in Plant by Hydrogel Microneedle Patch

The rapidly changing climate is exacerbating the environmental stress that negatively impacts crop health and yield. Timely sensing of plant response to stress is beneficial to timely adjust planting conditions, promoting the healthy growth of plants, and improving plant productivity. Hydrogen peroxide (H₂O₂) is an important molecule of signal transduction in plants. However, the common methods for detecting H₂O₂  in plants are associated with certain drawbacks, such as long extraction time, cumbersome steps, dependence on large instruments, and difficulty in realizing in-field sensing. Therefore, it is urgent to establish more efficient detection methods to realize the rapid detection of H₂O₂ content in plants. In this research, poly (methyl vinyl ether-alt-maleic acid) (PMVE/MA) hydrogel microneedle (MN) patch for rapid extraction of leaf sap are prepared, and the extraction mechanism of PEG-crosslinked PMVE/MA hydrogel MN patch is studied. A method of rapid detection of H₂O₂ content in plants based on MN patch with optical detection technology is constructed. The hydrogel MN patch can be used for timely H₂O₂ analysis. This application enables new opportunities in plant engineering, and can be extended to the safety and health monitoring of other plants and animals.