In the present work, we evaluated the effects of a mixture of biocontrol agents against two toxigenic strains of Penicillium expansum isolated in Argentine Patagonia from pome fruits. The two strains, INTA-5 and INTA-10, were previusly selected among ten strains coming from the Alto Valle (Rio Negro-Argentina) for their high production of patulin. For the biocontrol, Kosakonia radicincitans, Cryptococcus laurentii, and Rhodosporidium fluviale were tested in vitro experiments on Potato Dextrose Agar (PDA) dishes against the INTA-5 and INTA-10 strains.
View Article and Find Full Text PDFBackground: The epithelial cell adhesion molecule (EpCAM) is a biomarker that is highly overexpressed on the surface of epithelial carcinoma cells. In this study, silver nanoparticles covered with polyvinyl alcohol (AgNPs-PVA) were synthesized, characterized and used in a microfluidic immunosensor based on the use of anti-EpCAM recombinant antibodies as a trapping agent.
Methods: The concentration of trapped EpCAM is then electrochemically quantified by HRP-conjugated anti-EpCAM-antibody.
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.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFAims: to assess oxidative stress in acute pancreatitis, its evolution over time and its relationship with the severity of the disease.
Methods: during a two-year period, patients with acute pancreatitis with less than 24 hours of pain were evaluated. Serum was obtained the first, second and fourth day from admittance, if complications were detected, and after recovery.
In this article we report the development of an integrated microfluidic system coupled to a screen-printed carbon electrode (SPCE) applied to the quantitative determination of IgG specific antibodies present in serum samples of patients that suffer from Chagas disease. This relevant parasitic infection caused by the hemoflagellate protozoan Trypanosoma cruzi represents a major public health concern in Latin America. In order to perform the detection of mentioned antibodies, SPCE coupled to a microfluidic device was modified by electrodeposition of gold nanoparticles (AuNPs) and functionalized with Trypanosoma cruzi proteins from epimastigote membranes.
View Article and Find Full Text PDFOchratoxin A (OTA) is a mycotoxin produced by filamentous fungi of the genus Aspergillus and Penicillium that presents carcinogenic, teratogenic and nephrotoxic properties. In this work, we have developed, characterized and applied an immunoassay methodology comprised of magnetic nanoparticles (MNPs) as platform for immobilizing bioactive materials incorporated into a microfluidic system for rapid and sensitive quantification of Ochratoxin A (OTA) in apples (Red Delicious) contaminated with Aspergillus ochraceus. The sensor has the potential for automation and the detection of OTA was carried out using a competitive indirect immunoassay method based on the use of anti-OTA monoclonal antibodies immobilized on 3-aminopropyl-modified MNPs.
View Article and Find Full Text PDFThis work described the development and characterization of an electrochemical method using square wave voltammetry (SWV) combined with the use of modified magnetic nanoparticles (MNPs), which had shown a rapid and sensitive determination of ochratoxin A (OTA) in wine grapes (Cabernet Sauvignon, Malbec and Syrah) post-harvest tissues. The wine grapes were inoculated with Aspergillus ochraceus to obtain OTA in artificially infected samples. The OTA was directly determined using square-wave voltammetry.
View Article and Find Full Text PDFA wide range of plant species, including economically important crops such as vegetables, ornamentals, bulbs, and fundamentally fruits, can be affected by gray mold caused by the fungal pathogen Botrytis cinerea . This paper describes the development of a microfluidic immunosensor with micromagnetic beads (MMBs) coupled to carbon-based screen-printed electrodes (SPCEs) for the rapid and sensitive quantification of B. cinerea in apple (Red Delicious), table grape (pink Moscatel), and pear (William's) tissues.
View Article and Find Full Text PDFBotrytis cinerea is a plant-pathogenic fungus that produces the disease known as grey mould in a wide variety of agriculturally important hosts in many countries. This paper describes the development of an immunosensor coupled to carbon-based screen-printed electrodes (SPCE) modified with multi-walled carbon nanotubes (CNTs), which show a rapid and sensitive determination of B. cinerea in apple tissues (Red-delicious) using a competitive immunoassay method.
View Article and Find Full Text PDFFabrication of an amperometric-rotating biosensor for the enzymatic determination of cholesterol is reported. The assay utilizes a combination of three enzymes: cholesterol esterase (ChE), cholesterol oxidase (ChOx) and peroxidase (HRP); which were co-immobilizing on a rotatory disk. The method is developed by the use of a glassy carbon electrode as detector versus Ag/AgCl/3M NaCl in conjunction with a soluble-redox mediator 4-tert-butylcatechol (TBC).
View Article and Find Full Text PDFThe high sensitivity that can be attained using an enzymatic system and mediated by catechol has been verified by on-line interfacing of a rotating biosensor and continuous flow/stopped-flow/continuous-flow processing. Horseradish peroxidase, HRP [EC 1.11.
View Article and Find Full Text PDFThe high sensitivity that can be attained using an enzymatic system and mediated by catechols has been verified by on-line interfacing of a rotating biosensor and continuous flow/stopped-flow/continuous-flow processing. Horseradish peroxidase, HRP, [EC 1.11.
View Article and Find Full Text PDFThe roles of chemical kinetics and mass transfer in three types of bioreactors (packed-column reactors, rotating disk bioreactors and amperometric detector), used with continuous-flow sample/reagent(s) processing, are discussed in detail. A normalized quantitative comparison between these types of reactors clearly shows that rotating disk reactors afford a significantly more efficient utilization of active sites and permit the effective utilization of very small amounts of biocatalysts. Horseradish peroxidase (EC 1.
View Article and Find Full Text PDFThe high sensitivity that can be attained using an immunoassays coupled to a rotating bioreactor with electrochemical detection mediated by [Os(bpy)2Cl(pyCOOH)]Cl, has been verified for the detection of Trypanozoma cruzi (T. cruzi), This protozoan parasite causes Chagas disease, affecting more than 18 million people in central and south America. Antibodies in the serum sample are allowed to react immunologically with whole homogenates of the parasite as antigen that are immobilized on a rotating disk.
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