A Smartphone Integrated Platform for Ratiometric Fluorescent Sensitive and Selective Determination of Dipicolinic Acid.

A desirable lanthanide-based ratiometric fluorescence probe was designed as a multifunctional nanoplatform for the determination of dipicolinic acid (DPA), a unique bacterial endospore biomarker, with high selectivity and sensitivity. The carbon dots (CDs) with blue emission wavelengths at 470 nm are developed with europium ion (Eu3+) to form Eu3+/CDs fluorescent probes. DPA can specifically combine with Eu3+ and then transfer energy from DPA to Eu3+ sequentially through the antenna effect, resulting in a distinct increase in the red fluorescence emission peak at 615 nm. The fluorescence intensity ratio of Eu3+/CDs (fluorescence intensity at 615 nm/fluorescence intensity at 470 nm) showed good linearity and low detection limit. The developed ratiometric nanoplatform possesses great potential for application in complex matrices owing to its specificity for DPA. In addition, the integration of a smartphone with the Color Picker APP installed enabled point-of-care testing (POCT) with quantitative measurement capabilities, confirming the great potential of the as-prepared measurement platform for on-site testing.

Comparative study on growth traits and ions regulation of zoysiagrasses under varied salinity treatments.

Salt stress affects plant physiology, development, and growth. This research investigated varied salinity levels on growth traits and ions accumulation of four zoysiagrasses and aimed to identify phenotypic traits associated with variability in salinity tolerance. In this study, "S001" zoysiagrass (Zoysia sinica), "Diamond" zoysiagrass (Zoysia matrella), "J026" zoysiagrass (Zoysia japonica), and "M001" zoysiagrass (Zoysia macrostachya) were grown in plastic pots and exposed to 1/2 Hoagland nutrient solution amended with different amounts of NaCl for 120 days. At the end of the experiment, growth traits and ion contents were determined. The results showed that the salt-tolerance of four zoysiagrasses ranked as "M001" > "Diamond" > "J026" > "S001" according to percent green leaf canopy area (GLCA) after 120 days of salinity treatment. Although dry leaf weight, leaf length/width, and shoot height were significantly decreased by salinity treatments for all turfgrasses, the salt-tolerant species had a smaller drop. Besides, ions secretion capacity and Na+ concentration in leaf and root increased, but K+ concentration together with leaf and root K+/Na+ ratios decreased with the increasing concentration of the salinity. However, the salt-tolerant species exhibited strong K+ absorption and transportation ability and a high salt secretion capacity. The results indicated that growth traits and ions regulation were related to variability in tolerance of diverse zoysiagrasses to salt stress.