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In this work, the characterization of a solid-state ion-selective electrode (SS-ISE) by electrochemical impedance spectroscopy (EIS) was performed for potential detection of Pb2+ ions. This electrode is based on a PVC-membrane with an aroylthiourea derivative as ionophore. The solid transducer was prepared using an epoxy-graphite-graphene composite. The impedance analysis (from 20 Hz - 1 MHz) allows to describe the electrochemical response of the electrode in terms of the electrical processes in the membrane instead of the circuital elements related to the charge-transfer process at the transducer/membrane interface. The Pb2+ ions concentration was determined with this SS-ISE in aqueous solution by EIS using the electrical resistance of the membrane. The limit of detection reached by this approach was in the concentration range from 10-7 - 10-6 mol/L, one order of magnitude lower than the obtained by classical potentiometry. This analysis could be applied to the implementation of analytical determinations by EIS using SS-ISE. [ABSTRACT FROM AUTHOR]

In the present work, liposomes have been used as nanocarriers in the biofortification of wheat plants with selenium (Se) through foliar application. Liposomal formulations were prepared using 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and Phospholipon®90H (P90H) (average size <100 nm), loaded with different concentrations of inorganic Se (selenite and selenate) and applied twice to the plants in the stage of vegetative growth. Liposomes enhanced Se uptake by wheat plants compared to direct application. The highest Se enrichment was achieved using the phospholipid DPPC and a concentration of 1000 μmol·L -1 of Se without affecting the biomass, chlorophylls, carotenoids, and the concentration of mineral nutrients of the plants. The chemical speciation of Se in the plants was further investigated by X-ray absorption spectroscopy (XAS). The results from XAS spectra revealed that most of the inorganic Se was transformed to organic Se and that the use of liposomes influenced the proportion of C-Se-C over C-Se-Se-C species., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Kale (Brassica oleracea L. var. sabellica L.), kohlrabi (Brassica oleracea L. var. gongylodes L.) and wheat (Triticum aestivum L. cv. Bancal) microgreens were cultivated in presence of selenium 20 μmol L -1 as sodium selenite and sodium selenate mixture. The influence of this biofortification process was evaluated in terms of biomass production, total Se, macro- and micronutrients concentration, polyphenols, antioxidant activity, chlorophylls and carotenoids levels and total soluble proteins content. The results obtained have shown a significant concentration of total Se in the biofortified microgreens of kale (133 μg Se·g -1 DW) and kohlrabi (127 μg Se·g -1 DW) higher than that obtained for wheat (28 μg Se·g -1 DW). The Se uptake in all the species did not produce oxidative damage to the plants reflected in the bioactive compounds, antioxidant capacity or pigments concentration. These Se-enriched microgreens may contribute to the recommended intake of this nutrient in human diet as to overcome Se-deficiency., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)