Charneca, Portugal
Charneca, Portugal

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Fernandez-Costa C.,Hospital Universitario runa | Reboiro-Jato M.,University of Vigo | Fdez-Riverola F.,University of Vigo | Ruiz-Romero C.,Hospital Universitario runa | And 3 more authors.
Talanta | Year: 2014

Sequential chemical depletion of serum coupled to C18 sequential extraction of peptides as a rapid tool for human serum multiple profiling is herein presented. The methodology comprises depletion with DTT and then with ACN; the extract thus obtained is then summited to fast protein digestion using ultrasonic energy. The pool of peptides is subsequently concentrated using C18-based Zip-tips and the peptides are sequentially extracted using different concentrations of ACN. Each extract is mass-spectrometry profiled with MALDI. The different spectra thus obtained are then successfully used for classification purposes. A total of 40 people, comprising 20 healthy and 20 non-healthy donors, were successfully classified using this method, with an excellent q-value<0.05. The proposed method is cheap as it entails few chemicals, DTT and ACN, simple in terms of handling, and fast. In addition, the methodology is of broad application as it can be used for any study applied to serum samples or other complex biological fluids. © 2014 Elsevier Inc. All rights reserved.

Oliveira E.,BIOSCOPE Group | Oliveira E.,Royal University | Nunes-Miranda J.D.,BIOSCOPE Group | Santos H.M.,University of Barcelona | And 2 more authors.
Inorganica Chimica Acta | Year: 2012

Two new tyrosine Schiff-base ligands 1 and 2 bearing an indole or a thianaphthene moiety were synthesized and characterized by elemental analysis, 1H NMR, IR spectroscopy (KBr discs), MALDI-TOF-MS spectrometry, UV-Vis and fluorescence emission spectroscopy. The sensing ability towards Ca 2+, Zn 2+, Cd 2+, Cu 2+, Ni 2+, Hg 2+ and Al 3+ metal ions was explored in absolute ethanol. Both compounds showed colorimetric properties in the presence of Cu 2+ ions, changing their colour from light yellow to purple (1) and dark pink (2). The minimal amount of Cu 2+ that compounds 1 and 2 could quantify was ca. of 8 ppm. In order to obtain new nanomaterials based on the reported systems, new gold and silver nanoparticles were successfully synthesized by self-reduction of compound 1 in an aqueous alkaline environment. The nanoparticle formation was demonstrated by UV-Vis and fluorescence emission spectroscopy, dynamic light scattering and transmission electron microscopy (TEM). TEM images of AgNPs and AuNPs showed sizes of 12 ± 3.5 nm with monodispersed distribution, and 7.50 ± 6 nm with asymmetric average distribution, respectively. In the case of gold nanoparticles the polydisperse distribution suggested some nanoparticle aggregation. © 2011 Elsevier B.V. All rights reserved.

Oliveira E.,BIOSCOPE Group | Oliveira E.,Royal University | Lorenzo J.,Autonomous University of Barcelona | Cid A.,BIOSCOPE Group | And 2 more authors.
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2013

Two new fluorescent bio-inspired dyes 1 and 2 containing a fluorescein unit linked to a protected with a Boc group (N-tert-butyloxycarbonyl), and unprotected alanine residue were synthesized and characterized. The acid-base behavior was studied in water/ethanol (60/40) and at pH = 8 a strong emission fluorescence, followed by a color change from colorless to yellow was observed. Photophysical studies in water HEPES buffered solution toward alkaline, alkaline earth, transition, and post- transition metal ions were performed. Compounds 1 and 2 revealed to be very sensitive to Hg2+ with colorimetric changes from yellow to pink in the presence of HEPES buffer. Moreover, compound 1 show a color change from yellow to orange in the presence of the neurotransmitter molecule dopamine. Compound 2 also reveals to be sensitive to Cu2+ and Ni2+ , being able to detected and quantified in HEPES buffer ca. 0.37 ppm and ca. 1.50 ppm of Cu2+ , respectively. Very small silver nanoparticles coated with compound 2 of ca. 3.68 ± 0.93 nm were successfully synthesized and characterized. Toxicological studies with both compounds were also carried out. © 2013 Elsevier B.V.

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