Chitosan-GSNO nanoparticles: a positive modulator of drought stress tolerance in soybean.

BACKGROUND: Chitosan biopolymer is an emerging non-toxic and biodegradable plant elicitor or bio-stimulant. Chitosan nanoparticles (CSNPs) have been used for the enhancement of plant growth and development. On the other hand, NO is an important signaling molecule that regulates several aspects of plant physiology under normal and stress conditions. Here we report the synthesis, characterization, and use of chitosan-GSNO nanoparticles for improving drought stress tolerance in soybean. RESULTS: The CSGSNONPs released NO gas for a significantly longer period and at a much lower rate as compared to free GSNO indicating that incorporation of GSNO in CSNPs can protect the NO-donor from rapid decomposition and ensure optimal NO release. CS-GSNONPs improved drought tolerance in soybean plants reflected by a significant increase in plant height, biomass, root length, root volume, root surface area, number of root tips, forks, and nodules. Further analyses indicated significantly lower electrolyte leakage, higher proline content, higher catalase, and ascorbate peroxidase activity, and reduction in MDA and H2O2 contents after treatment with 50 µM CS-GSNONPs under drought stress conditions. Quantitative real-time PCR analysis indicated that CS-GSNONPs protected against drought-induced stress by regulating the expression of drought stress-related marker genes such as GmDREB1a, GmP5CS, GmDEFENSIN, and NO-related genes GmGSNOR1 and GmNOX1. CONCLUSIONS: This study highlights the potential of nano-technology-based delivery systems for nitric oxide donors to improve plant growth, and development and protect against stresses.

Biodegradable metal-organic framework MIL-88A for triboelectric nanogenerator.

Metal-organic frameworks (MOFs) are multifunctional materials with a unique advantage of high porosity and surface area and size tunability and can be modified without altering the topology. The interesting and desirable properties of MOFs led to their exploration for the triboelectric nanogenerator. Herein, a biodegradable MOF MIL-88A for TENG (MIL-TENG) is reported. MIL-88A can be easily synthesized by coordinating iron chloride and fumaric acid in water, thus offering eco-friendly synthesis. Various materials are selected as opposite layers to MIL-88A to analyze triboelectric behavior and performance. The MIL-TENG exhibits an output trend of TENGEC < TENGKapton < TENGFEP. The MIL-88A and FEP generated an output voltage of 80 V and an output current of 2.2 µA. The surface potential measurement and electrical output trend suggest the positive triboelectric behavior of MIL-88A concerning FEP and Kapton. The utilization of biomechanical motions and numerous low-rating electronics powered via a capacitor are demonstrated.

Metal-Amino Acid Nanofibers based Triboelectric Nanogenerator for Self-Powered Thioacetamide Sensor.

The biomolecules offer different metal-binding sites to form a coordination polymer with structural diversity. The coordination directed one-dimensional metal-biomolecule nanofibers (Cu-Asp NFs) designed using copper as metal ion and aspartate as a ligand for triboelectric nanogenerator (TENG) is reported here. The different characterization techniques reveal the detailed characteristics of the synthesized Cu-Asp NFs. The robust coating of the Cu-Asp NFs is achieved using a simple tape cast coater. The bending and water dipping studies suggest the stability of the coated material. The relative polarity test and Kelvin probe force microscopy (KPFM) reveal the position of Cu-Asp in the triboelectric series. The Cu-Asp NFs and Teflon are used as the active material for the fabrication of freestanding mode (NF-TENG) and contact-separation mode (cNF-TENG) TENG. The NF-TENG generates an output of 200 V and 6 µA. The simple ion deposition technique enhances the voltage, current, and transferred charge of cNF-TENG by 2.5, 8, and 3 times. The use of the material for the single electrode sliding mode device further confirms the coated material's stability and robustness. A selective self-powered thioacetamide sensor is developed with the cNF-TENG, which exhibits a sensitivity of 0.76 v mM-1. Finally, NF-TENG is demonstrated for powering up numerous portable electronics.