Graphene-based materials as solid phase extraction sorbent for chromium(VI) determination in red wine

We report a novel and selective method for the preconcentration and determination of Cr(VI) in red wine through their adsorption on a tertiary amine, ALIQUAT 336, a commercial anionic exchanger extractant, widely used for the selective extraction of Cr(VI) over Cr(III). The determinations were made directly on the solid, by X-ray fluorescence spectrometry, method and large areas held by the graphene, making them a promising solid sorbent for preconcentration procedures, direct quantification of the analyte in the solid sorbent; there by reducing the number of reagents used thus minimizing handling of the sample. A high preconcentration factor was achieved for a very low volume of sample. The enrichment factor was calculated after considering that the thin film obtained from the 10 mL solution of 1 mg L−1 of Cr(VI) has a real thickness of 0.04 mm and a final diameter of 16.7 mm, so that the volume deposited on the pellet was 0.0088 cm3 and the preconcentration factor can be calculated to be 104.Fil: Fernández, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Aranda, Pedro Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentin

Detection transposable elements in Botrytis cinerea in latent infection stage from symptomless apples

Detection of Botrytis cinerea latent infections on apples before storage is essential for effective control strategies in the fruit postharvest industry. In the present study a PCR detection method, based on primers designed on B. cinerea transposable elements (boty and flipper) and intergenic spacer (IGS) region as internal control were utilized to reveal the presence of symptomless infections on apple fruits. The method molecular proved to be highly specific and sensitive in detecting latent infections, revealed the presence of the pathogen in 83% of the samples from infected apples with 104 conidia/mL, whereas those infected with 106 conidia/mL detected 94% as compared to the traditional method that revealed the pathogen in 40 and 66% of the samples inoculated with 104 and 106 conidia/mL respectively. Furthermore, the method characterized B. cinerea as subpopulation transposa-type by the presence of the transposable elements boty and flipper The results obtained of DNA quantification method were compared with ELISA assay and these studies showed good correlation. Therefore our method has important advantages compared with others detection methods for B. cinerea, because the proposed methodology allowed distinguishes between its two subpopulations (vacuma and transposa) and this would allow establish possible control appropriate strategies. Finally, the method can be an interesting alternative for its possible application in the phytosanitary programs of the fruit industry worldwide.Fil: Fernández, Jorge Gastón. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Muñoz, Claudio Javier. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza - San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Salinas, Eloy. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Sanz Ferramola, Maria Isabel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin

Development of nitrocellulose membrane filters impregnated with different biosynthesized silver nanoparticles applied to water purification

Bactericidal water filters were developed. For this purpose, nitrocellulose membrane filters were impregnated with different biosynthesized silver nanoparticles. Silver nanoparticles (AgNPs) from Aspergillus niger (AgNPs-Asp), Cryptococcus laurentii (AgNPs-Cry) and Rhodotorula glutinis (AgNPs-Rho) were used for impregnating nitrocellulose filters. The bactericidal propertie of these nanoparticles against Escherichia coli, Enterococcus faecalis and Pseudomona aeruginosa were successfully demonstrated. The higher antimicrobial effect was observed for AgNPs-Rho. This fact would be related not only to the smallest particles, but also to polysaccharides groups that surrounding these particles. Moreover, in this study, complete inhibition of bacterial growth was observed on nitrocellulose membrane filters impregnated with 1mgL-1 of biosynthesized AgNPs. This concentration was able to reduce the bacteria colony count by over 5 orders of magnitude, doing suitable for a water purification device.Fil: Fernández, Jorge Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Almeida, César Américo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Felici, Carlos Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Sanz, María I.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina. Área de Tecnología Química y Biotecnología; Argentin

Development of a nanostructured electrochemical immunosensor applied to the early detection of invasive aspergillosis

The use of a biological marker as an adjunct for screening for invasive aspergillosis (IA) in high-risk patients is attractive, because it is noninvasive and may detect evidence of IA prior to the appearance of clinical signs and symptoms. Galactomannan (GMN) is a polysaccharide cell-wall component that is released by Aspergillus species. In the present work, an electrochemical microfluidic immunosensor for GMN detection was developed. Moreover, copper nanoparticles covered with polyvinylpyrrolidone (CuNPs-PVP) were synthesized, characterized and used in a microfluidic immunosensor based on the use of anti-GMN antibodies as a trapping agent. The concentration of trapped GMN is then electrochemically quantified by HRP-conjugated anti-GMN-antibody. HRP reacted with its enzymatic substrate in a redox process which resulted in the appearance of a current whose magnitude is directly proportional to the concentration of GMN. The immunosensor was validated by analyzing patient samples, and a good correlation with a commercial ELISA was obtained. This microfluidic immunosensor can be applied to the early diagnosis of IA.Fil: Piguillem Palacios, Sofía Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Ortega Sánchez, Francisco Gabriel. Weizmann Institute of Science; IsraelFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Cadmium-induced oxidative damage and antioxidant defense mechanisms in Glycine max L.

Objective: To analyze the effect of Cadmium (Cd) on the metabolism of reduced glutathione (GSH) in roots and leaves of Glycine max L. Methods: A capillary electrophoresis methodology was optimized to determinate simultaneously GSH and reduced and oxidized GSH in a precise and accurate way. The functional role of the genes involved in GSH cellular metabolism (γ-glutamylcysteine synthetase), GSH synthetase and glutathione reductase (GR) was evaluated. Finally, the activities of antioxidant enzymes as GR and superoxide dismutases were determinate. Results: The studies of γ-glutamylcysteine synthetase and GSH synthetase gene expression showed an increase and GR showed a decrease in Cd-treated plants. GR and superoxide dismutases activities increased at 24 h and 6 h respectively in roots under Cd exposure. GSH content was higher and showed a significant increase in roots and leaves at 6 h and 24 h of treatment. Conclusions: The results of the present study showed a better understanding in signaling pathway by alterations in antioxidant mechanisms by Cd in soybean seedlings.Fil: Felici, Carlos Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Molina, Alicia. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; ArgentinaFil: Almeida, César Américo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Zirulnik, Fanny. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Gomez, Maria Roxana Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentin

Electrochemical microfluidic immunosensor based on TES-AuNPs@Fe3O4 and CMK-8 for IgG anti-Toxocara canis determination

We report a microfluidic immunosensor for the electrochemical determination of IgG antibodies anti-Toxocara canis (IgG anti-T. canis). In order to improve the selectivity and sensitivity of the sensor, core-shell gold-ferric oxide nanoparticles (AuNPs@Fe3O4), and ordered mesoporous carbon (CMK-8) in chitosan (CH) were used. IgG anti-T. canis antibodies detection was carried out using a non-competitive immunoassay, in which excretory secretory antigens from T. canis second-stage larvae (TES) were covalently immobilized on AuNPs@Fe3O4. CMK-8-CH and AuNPs@Fe3O4 were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometry, cyclic voltammetry, electrochemical impedance spectroscopy, and N2 adsorption-desorption isotherms. Antibodies present in serum samples immunologically reacted with TES, and then were quantified by using a second antibody labeled with horseradish peroxidase (HRP-anti-IgG). HRP catalyzes the reduction from H2O2 to H2O with the subsequent oxidation of catechol (H2Q) to p-benzoquinone (Q). The enzymatic product was detected electrochemically at _100 mV on a modified sputtered gold electrode. The detection limit was 0.10 ng mL−1, and the coefficients of intra- and inter-assay variation were less than 6%, with a total assay time of 20 min. As can be seen, the electrochemical immunosensor is a useful tool for in situ IgG antibodies anti-T. canis determination.Fil: Jofre, Claudio Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Regiart, Daniel Matias Gaston. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Bertotti, Mauro. Universidade de Sao Paulo; BrasilFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Study of antitumor activity in breast cell lines using silver nanoparticles produced by yeast

In the present article, we describe a study of antitumor activity in breast cell lines using silver nanoparticles (Ag NPs) synthesized by a microbiological method. These Ag NPs were tested for their antitumor activity against MCF7 and T47D cancer cells and MCF10-A normal breast cell line. We analyzed cell viability, apoptosis induction, and endocytosis activity of those cell lines and we observed that the effects of the biosynthesized Ag NPs were directly related with the endocytosis activity. Moreover, Ag NPs had higher inhibition efficacy in tumor lines than in normal lines of breast cells, which is due to the higher endocytic activity of tumor cells compared to normal cells. In this way, we demonstrate that biosynthesized Ag NPs can be an alternative for the treatment of tumors.Support from Universidad Nacional de San Luis, to the Agencia Nacional de Promoción Científica y Tecnológica, from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina), and from GENYO, Centre for Genomics and Oncological Research: Pfizer-University of Granada, Andalusian Regional Government, Granada, Spain are acknowledged

Novel electrochemical sensing platform based on a nanocomposite of PVA / PVP / RGO applied to IgG anti- Toxoplasma gondii antibodies quantitation

This article describes the development of a new electrochemical platform composed by a polymer mixture and graphene oxide (GO). The working electrode of a screen-printed carbon electrode (SPCE) was modified with nanocomposite constituted by poly-vinyl alcohol (PVA), poly-vinylpyrrolidone (PVP) and GO, which was electrochemically reduced to obtain PVA/PVP/RGO/SPCE. The interactions and morphology of the PVA/PVP/GO nanocomposite were investigated by SEM, FTIR and UV-Vis. SEM images indicated an excellent dispersion of the GO sheets in the polymer matrix. Besides, FTIR and visible UV studies revealed strong interactions between polymer mixture and GO sheets. According to electrochemical studies, the new platform increased the electroactive surface area by a factor of 20.46 compared to the unmodified SPCE. Also, the PVA/PVP/RGO/SPCE had a fast electron kinetics transfer process with a value of ks = 9.6 s-1.The modified electrode was applied to the determination of IgG anti-T. gondii antibodies for the serological diagnosis of toxoplasmosis. The IgG anti-T. gondii antibodies quantification showed a detection limit of 0.012 U mL-1, and the coefficients of variation intra-day and inter-day assays were lower than 4.5% and 6.2%, respectively. The electrochemical platform proved to be a sensitive and easily applicable tool applied to the serological diagnosis of toxoplasmosis. Therefore, the developed nanocomposite represents an excellent alternative for the electrochemical biosensor fabrication.Fil: Takara, Eduardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Scala Benuzzi, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Zinc oxide nanoparticles based microfluidic immunosensor applied in congenital hypothyroidism screening

In this article, we present an innovative approach for congenital hypothyroidism (CHT) screening. This pathology is the most common preventable cause of mental retardation, affecting newborns around the world. Its consequences could be avoided with an early diagnosis through the thyrotropin (TSH) level measurement. To accomplish the determination of TSH, synthesized zinc oxide (ZnO) nanobeads (NBs) covered by chitosan (CH), ZnO-CH NBs, were covalently attached to the central channel of the designed microfluidic device. These beads were employed as platform for anti-TSH monoclonal antibody immobilization to specifically recognize and capture TSH in neonatal samples without any special pretreatment. Afterwards, the amount of this trapped hormone was quantified by horseradish peroxidase (HRP)-conjugated anti-TSH antibody. HRP reacted with its enzymatic substrate in a redox process, which resulted in the appearance of a current whose magnitude was directly proportional to the level of TSH in the neonatal sample. The structure and morphology of synthesized ZnO-CH NBs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The calculated detection limits for electrochemical detection and the enzyme-linked immunosorbent assay procedure were 0.00087 μUI mL-1 and 0.015 μUI mL-1, respectively, and the within- and between-assay coefficients of variation were below 6.31 % for the proposed method. According to the cut-off value for TSH neonatal screening, a reasonably good limit of detection was achieved. These above-mentioned features make the system advantageous for routine clinical analysis adaptation.Fil: Seia, Marco Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: de Vito, Irma Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin