The speciation of most biologically active trace metals in seawater is dominated by complexation by organic ligands. This review traces the history of work in this area, from the early observations that showed surprisingly poor recoveries using metal preconcentration protocols to the present day, where advances in mass spectroscopy and stable isotope geochemistry are providing new insights into the structure, origin, fate, and biogeochemical impact of organic ligands. Many long-standing hypotheses about the specific biological origin of ligands such as siderophores in seawater are finally being validated. This work has revealed the complexity of organic complexation, with multiple ligands and, in some cases, timescales of ligand exchange that are much slower than originally thought. The influence of organic complexation on scavenging is now a key parameter in biogeochemical models of biologically essential metals, especially iron. New insights about the sources and sinks of ligands are required to enhance the usefulness of these models.
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http://dx.doi.org/10.1146/annurev-marine-033023-083652 | DOI Listing |
Chemistry
January 2025
Institute of Chemical Research of Catalonia: Institut Catala d'Investigacio Quimica, -, Av. Països Catalans 16, 43007, Tarragona, SPAIN.
Noncovalent interactions are present in numerous synthetic and biological systems, playing an essential role in vital processes for life such as stabilization of proteins' structures or reversible binding in substrate-receptor complexes. Their study is relevant, but it presents challenges due to its inherent weak nature. In this context, molecular balances (MBs) are one of the most efficient physical organic chemistry tools to quantify noncovalent interactions, bringing beneficial knowledge regarding their nature and strength.
View Article and Find Full Text PDFACS ES T Water
January 2025
School of Earth and Environmental Sciences, Queens College, City University of New York, Queens, New York 11367, United States.
Scaling minerals, such as barite, can cause detrimental consequences for oil/gas pipelines and water systems, but their formation can be inhibited by organic chelators such as ethylenediaminetetraacetic acid (EDTA). Here, we resolve how EDTA affects sorption and desorption of Pb at the barite (001) surface using a combination of X-ray scattering and microscopy measurements. In the presence of EDTA, Pb incorporated in the topmost part of the barite surface and adsorbed as inner-sphere complexes on the surface.
View Article and Find Full Text PDFScientificWorldJournal
January 2025
Department of Prosthodontics, Indira Gandhi Institute of Dental Sciences, Nellikuzhi, Kothamangalam 686691, Kerala, India.
Dental caries causes mineral loss and organic damage to teeth. Understanding caries and dentin pulp reactions is crucial for effective caries management strategies. There is a lack of knowledge regarding the microscopic and ultramicroscopic changes that occur during caries destruction and reactive changes.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Mineralogical Society of Antwerp, Boterlaarbaan 225, 2100 Deurne, Belgium.
ConspectusWhile photochromic natural sodalites, an aluminosilicate mineral, were originally considered as curiosities, articles published in the past ten years have radically changed this perspective. It has been proven that their artificial synthesis was easy and allowed compositional tuning. Combined with simulations, it has been shown that a wide range of photochromic properties were achievable for synthetic sodalites (color, activation energy, reversibility, etc.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials and Energy, Lanzhou University (LZU), Lanzhou 730000, China.
Complementary neural network circuits combining multifunctional high-performance p-type with n-type organic artificial synapses satisfy sophisticated applications such as image cognition and prosthesis control. However, implementing the dual-modal memory features that are both volatile and nonvolatile in a synaptic transistor is challenging. Herein, for the first time, we propose a single vertical n-type organic synaptic transistor (VNOST) with a novel polymeric organic mixed ionic-electronic conductor as the core channel material to achieve dual-modal synaptic learning/memory behaviors at different operating current densities via the formation of an electric double layer and the reversible ion doping.
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