Por: Saúl Vallejos, Asunción Muñoz, Saturnino Ibeas, Felipe Serna, Félix Clemente García, José Miguel García. En: J. Mater. Chem. A, 2013,1, 15435-15441. DOI:  10.1039/C3TA12703F Investigadores de la Universidad de Burgos han desarrollado un material inteligente que cambia de color según el hierro que lleve un fluido, sea agua, vino o suero sanguíneo. Después, si se fotografía el resultado con una cámara digital, como la de los teléfonos celulares, se puede cuantificar la concentración de este metal sin necesidad de análisis químicos. La técnica consiste en depositar una gota del fluido sobre el material -un fino disco de medio centímetro de diámetro y 0,1 mm grosor-, esperar quince minutos y comparar el resultado con un patrón. Esto se puede hacer a simple vista, pero si se fotografía la lámina con el celular, se puede cuantificar mejor la concentración de este metal de gran importancia biológica e industrial. Los datos de color RGB (rojo, verde y azul) se pueden obtener directamente desde el móvil y procesar en un ordenador convencional, para establecer los niveles del catión según el sistema de referencia. Iron in blood serum, wine and water has been visually detected and quantified quickly by processing photographs of an iron colorimetric sensory polymer substrate. The photographs may be taken with a conventional digital camera or Smartphone. The sensory materials were designed following a straightforward strategy. A proven iron organic chelator was easily transformed into an acrylic monomer and further copolymerized with hydrophilic co-monomers to render a membrane comprised of a hydrophilic, gel-like, polymer network. The film-like membrane generated was cut into small-diameter sensory discs. Thus, upon immersion of the sensory disks in blood serum, wine, and water, a colour development was rapidly observed which could be easily correlated with the iron concentration of the samples. RGB digital parameters obtained from photographs of the sensors were processed statistically using principal component analysis (PCA) and used to elaborate titration curves and quantify iron concentrations. The response time of the sensory films was short, 15 min, and the concentrations measured in water ranged from 56 ppb to 56 ppm. This broad range covers the U.S. Environmental Protection Agency (EPA) and European Union (EU) drinking water standards for iron in drinking water (<300 and 200 ppm, respectively), the typical iron content in wines (1 to 10 ppm) and the normal range of iron in the blood serum in men (0.8-1.8 ppm). This methodology for detecting and quantifying chemical species avoids the time-consuming sample preparation, expensive laboratory techniques, and specialized personnel needed to carry out conventional analytical methods.