Transition metal ions have proved to be essential for Life, though it is well known that they can also be toxic at excessive concentrations. Consequently, sensing and quantification of metal ions in the environment is essential for controlling the pollution levels in waters, soils and air.
We took profit of our experience in the design of fluorescent chelators to be used within the cell and develop to metal ion sensors which give a specific response to different metal ions in different types of matrices. We design chelators with variable physical properties in order to adapt their use in waters with different pH and salinity characteristics and in soils.
Most commonly we couple metal ion chelators to fluorophores or other spectroscopic probes. We strategically couple chelators to fluorophores in order to produce molecules that exhibit ‘OFF/ON’ or ‘ON/OFF’ response. More recently we are interested in the preparation of new organic-inorganic hybrid materials that allow the simultaneous detection, quantification and removal of target metal ions in different matrices.
New hydrophilic 3-hydroxy-4-pyridinone chelators with ether-derived substituents: synthesis and evaluation of analytical performance in the determination of iron in waters, Moniz, Tânia - Cunha-Silva, Luis, Mesquita, Raquel, Silva, Andre Silva, Ana, Rangel, António, de Castro, Baltazar, Rangel, Maria, Polyhedron, 2019, 160, 145-156; https://dx.doi.org/10.1016/j.poly.2018.12.005.
Measurement of iron(III) in waters by microsequential injection solid phase spectrometry using an hexadentate 3-hydroxy-4-pyridinone chelator as reagent, Joana Miranda, Raquel Mesquita, Ana Nunes, Maria Rangel, António Rangel, Talanta, 2019, 191, 409–414; https://dx.doi.org/10.1016/j.talanta.2018.08.063.
Microsequential Injection LAB-ON-VALVE System for the Spectrophotometric determination of Iron and Copper, Alba González, Raquel B.R. Mesquita, Jessica Avivar, Tania Moniz, Maria Rangel, Víctor Cerdà, António O.S.S. Rangel, Talanta, 2017, 167, 703–708.; http://dx.doi.org/10.1016/j.talanta.2017.02.055.
Design of a water soluble fluorescent 3-hydroxy-4-pyridinone ligand active at physiological pH values, Andreia Leite; Ana Silva; Catarina Coutinho; Luís Silva; Baltazar Castro; Maria Rangel, Journal of Fluorescence, 2016, 26, 1773–1785.; http://dx.doi.org/10.1007/s10895-016-1869-1
Synthesis and characterization of a 3-hydroxy-4-pyridinone chelator functionalized with a polyethylene glycol (PEG) chain aimed at sequential injection determination of iron in natural waters, Raquel B. R. Mesquita, Tânia Moniz, Joana L. A. Miranda, Vânia Gomes, André M. N. Silva, J. E. Rodriguez-Borges, António O. S. S. Rangel, Maria Rangel, Polyhedron, 2015, 101, 171-178.; http://dx.doi.org/10.1016/j.poly.2015.09.015.