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 (H 2 O 2 ) is an important molecule of signal transduction in plants. However, the common methods for detecting H 2 O 2 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 H 2 O 2 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 H 2 O 2 content in plants based on MN patch with optical detection technology is constructed. The hydrogel MN patch can be used for timely H 2 O 2 analysis. This application enables new opportunities in plant engineering, and can be extended to the safety and health monitoring of other plants and animals.
Concerns over health risks associated with mixed pesticide residues have led to a demand for rapid analytical methods. We present a portable surface-enhanced Raman spectroscopy (SERS) device specifically designed for real-time monitoring of indoxacarb (INDX) and chlorfenapyr (CFP) in vegetable juice. This point-of-use sensor integrates silver nanoparticles with a metal-organic framework (Ag/MOF-808(Zr)) and employs a 19-well quartz plate alongside a portable Raman spectroscopy instrument, facilitating simultaneous adsorption, separation, and detection. Detection limits for INDX and CFP in ginger and spinach juices were 0.26–0.76 ppb. Notably, results closely matched those from liquid chromatography, and in-situ detection was achieved within 2 min without pre-treatment, significantly enhancing efficiency over conventional chromatographic methods. This innovative approach demonstrates substantial potential for detecting pesticide mixtures in non-laboratory settings, presenting a valuable option for point-of-use applications.
Wang Li,Zihao Chen,Jiali Ren,Tao Yang,Qinlu Lin,Juewen Liu
Using simple and commonly available devices for signal reading has attracted much attention recently for DNA-based sensors. Most previous works focused on electrochemical or colorimetric signals. In this work, a portable device was structured by simple electronic and 3D-printed components to convert fluorescence signal to electric resistance with reading by a multimeter. To demonstrate its application, we took advantage of the slow ligand bind kinetics of Cr 3+ to promote DNA adsorption on metal oxide nanoparticles (MONPs). Nanoceria (CeO 2 ), screened from a total of 13 kinds of MONPs, possesses high specificity for Cr 3+ from other metal ions. EDTA can mask other metal ions, while it cannot bind Cr 3+ quickly so that Cr 3+ promotes DNA adsorption and thus fluorescence quenching. The linear range is from 0 to 2 μM Cr 3+ with a LOD of 0.02 μM. Using common electronic components and the 3D-printed miniaturized device, the sensor to transfer fluorescence to electric resistant signal was also measured by a digital multimeter. In this case, the LOD is about 1 μM Cr 3+ . Such a strategy may provide a simple and general approach for fluorescent portable device fabrication and may find applications for other onsite sensing applications.
危险品化学品经营许可证（带存储）