Forced Solid-State Interactions for the Selective “Turn-On” Fluorescence Sensing of Aluminum Ions in Water Using a Sensory Polymer Substrate

Selective and sensitive solid sensory substrates for detecting Al(III) in pure water are reported. The material is a flexible polymer film that can be handled and exhibits gel behavior and membrane performance. The film features a chemically anchored salicylaldehyde benzoylhydrazone derivative as an aluminum ion fluorescence sensor. A novel procedure for measuring Al(III) at the ppb level using a single solution drop in 20 min was developed. In this procedure, a drop was allowed to enter the hydrophilic material for 15 min before a 5 min drying period. The process forced the Al(III) to interact with the sensory motifs within the membrane before measuring the fluorescence of the system. The limit of detection of Al(III) was 22 ppm. Furthermore, a water-soluble sensory polymer containing the same sensory motifs was developed with a limit of detection of Al(III) of 1.5 ppb, which was significantly lower than the Environmental Protection Agency recommendations for drinking water.Spanish Ministerio de Economía y Competitividad-Feder (MAT2011-22544) and by the Consejería de Educación - Junta de Castilla y León (BU232U13)

Characterization and in vitro sensitivity of cholinesterases of gilthead seabream (Sparus aurata) to organophosphate pesticides

The characterization of cholinesterase activity in brain and muscle of gilthead seabream was carried out using four specific substrates and three selective inhibitors. In addition, K m and V max were calculated from the Michaelis–Menten equation for ASCh and BSCh substrates. Finally, the in vitro sensitivity of brain and muscle cholinesterases to three organophosphates (OPs) was also investigated by estimating inhibition kinetics. The results indicate that AChE is the enzyme present in the brain, whereas in muscle, a typical AChE form is present along with an atypical form of BChE. Very low ChE activity was found in plasma with all substrates used. The inhibitory potency of the studied OPs on brain and muscle AChEs based on bimolecular inhibition constants (k i ) was: omethoate < dichlorvos < azinphosmethyl-oxon. Furthermore, muscle BChE was found to be several orders of magnitude (from 2 to 4) more sensitive than brain and muscle AChE inhibition by dichlorvos and omethoate.This work was supported by Plan Nacional de I + D, Sciences and Technology Minister (Project: CTM2004-05718) and in part by Plan Andaluz de Investigación (PAI group: RNM-345).Peer reviewe

Sensitivity versus toxicity of inorganic and organic contaminants in sedentary and benthic larvae and adult fish species. Biomarkers of Exposure and Effect

Trabajo presentado en el XVI Seminario Ibérico de Química Marina, celebrado en Cádiz del 24 al 26 de enero de 2012.Se realiza una revisión de biomarcadores de estrés o específicos de diferentes contaminantes orgánicos (plaguicidas, hidrocarburos aromáticos policíclicos, dioxinas) e inorgánicos (metales) en diferentes especies de peces (larvas y adultos) de hábitos sedentarios y bentónicos, a nivel bioquímico, celular y molecular. Los resultados que se discuten proceden de experimentos en distintas condiciones experimentales (agua- sedimento-vía trófica). La toxicidad de los contaminantes (mortalidad, histopatología) es progresiva con la concentración del tóxico, siendo las larvas de peces en diferentes fases de su desarrollo (fase endo-exotrófica) más resistente a los contaminantes, en general, que los ejemplares adultos. Los órganos diana frente a contaminantes orgánicos e inorgánicos son preferentemente las branquias y el hígado (vía aguasedimento) y el tracto digestivo cuando la exposición es vía trófica, siendo el sistema nervioso el órgano diana para plaguicidas organofosforados. Existe una correlación significativa (positiva o negativa) entre la inducción de EROD y CYP1A en peces expuestos a benzo(a)pireno y dioxinas. Las respuestas tóxicas de los metales permiten corroborar sus efectos a nivel fisiológico y patológico subcelular: osmoregulación (células de cloruro); respiración (células pilares), y mecanismos protectores (células mucosas). La peroxidación lipídica es evidenciada en ejemplares expuestos tanto a contaminantes inorgánicos y orgánicos.Peer Reviewe