New methodologies in food analysis using nanoparticles

El objetivo genérico de las investigaciones que constituyen esta Memoria ha sido el desarrollo de métodos rápidos para el análisis de alimentos utilizando, básicamente, las especiales propiedades que presentan distintos nanomateriales. Los nanomateriales han presentado una amplia aplicabilidad en bioanálisis [1-3], pero su utilidad analítica en otras áreas de aplicación, tales como análisis de alimentos y ambiental ha sido más restringida. Los estudios realizados han pretendido expandir la aplicabilidad analítica de la Nanotecnología para abrir nuevas vías, alternativas a las ya establecidas, que mejoren el control de la calidad alimentaria. Para alcanzar este objetivo se han realizado las siguientes investigaciones: 1) Síntesis y caracterización de nanopartículas de sílice dopadas con los fluoróforos de larga longitud de onda azul nilo y violeta de cresilo y su utilización para formar marcadores aplicables a la determinación de macromoléculas y moléculas pequeñas en alimentos mediante inmunoensayo heterogéneo. 2) Desarrollo de nuevas metodologías analíticas para la determinación de parámetros globales en alimentos, tales como la capacidad antioxidante y contenido de polifenoles, utilizando fluorimetría de larga longitud de onda y nanopartículas de óxido de terbio, respectivamente. 3) Estudio sistemático de la utilidad del fenómeno de transferencia de energía de resonancia luminiscente (LRET) entre nanocristales de iones lantánidos, que presentan luminiscencia anti-Stokes (¿upconverting nanophosphors¿), y fluoróforos orgánicos para la determinación de biotina mediante ensayos de afinidad en medio homogéneo

Use of nile blue-doped silica nanoparticles as labels in heterogeneous immunoassays for antibiotic determination

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Long-wavelength homogeneous fluoroimmunoassay for the veterinary antibiotic monensin using nile-blue doped silica nanoparticles

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Developments in nanoparticles for use in biosensors to assess food safety and quality

The following will provide an overview on how advances in nanoparticle technology have contributed towards developing biosensors to screen for safety and quality markers associated with foods. The novel properties of nanoparticles will be described and how such characteristics have been exploited in sensor design will be provided. All the biosensor formats were initially developed for the health care sector to meet the demand for point-of-care diagnostics. As a consequence, research has been directed towards miniaturization thereby reducing the sample volume to nanolitres. However, the needs of the food sector are very different which may ultimately limit commercial application of nanoparticle based nanosensors. © 2014 Elsevier Ltd

Type I interferon supports inducible nitric oxide synthase in murine hepatoma cells and hepatocytes and during experimental acetaminophen-induced liver damage

Cytokine regulation of high-output nitric oxide (NO) derived from inducible NO synthase (iNOS) is critically involved in inflammation biology and host defense. Herein, we set out to characterize the role of type I interferon (IFN) as potential regulator of hepatic iNOS in vitro and in vivo. In this regard, we identified in murine Hepa1-6 hepatoma cells a potent synergism between pro-inflammatory interleukin-β/tumor necrosis factor-α and immunoregulatory IFNβ as detected by analysis of iNOS expression and nitrite release. Upregulation of iNOS by IFNβ coincided with enhanced binding of signal transducer and activator of transcription-1 to a regulatory region at the murine iNOS promoter known to support target gene expression in response to this signaling pathway. Synergistic iNOS induction under the influence of IFNβ was confirmed in alternate murine Hepa56.1D hepatoma cells and primary hepatocytes. To assess iNOS regulation by type I IFN in vivo, murine acetaminophen (APAP)-induced sterile liver inflammation was investigated. In this model of acute liver injury, excessive necroinflammation drives iNOS expression in diverse liver cell types, among others hepatocytes. Herein, we demonstrate impaired iNOS expression in type I IFN receptor-deficient mice which associated with diminished APAP-induced liver damage. Data presented indicate a vital role of type I IFN within the inflamed liver for fine-tuning pathological processes such as overt iNOS expression

Optical detection of different phenolic compounds by means of a novel biosensor based on sol-gel immobilized laccase

A novel sol-gel based biosensor exploiting the optical absorption properties of sol-gel immobilized laccase has been constructed in the attempt to increase enzyme specificity towards different phenolic substrates. Laccase from Trametes versicolor has been immobilized in optically transparent sol-gel matrices. Using Fourier transform infrared spectroscopy and data analysis based on a wavelet algorithm the successful enzyme immobilization has been evidenced. The changes in the optical absorption spectra of laccase reaction products at 425 nm, 375 nm and 400 nm have been used for hydroquinone, resorcinol and catechol concentration determination, respectively. Due to the slow response time of hydroquinone-laccase reaction, our optical biosensor has been tested with resorcinol and catechol. Linear ranges up to 1.4 mM and 0.2 mM, limit-of-detection (LOD) of 4.5 μM and 0.6 μΜ have been evidenced for resorcinol and catechol, respectively. Data for resorcinol concentration determination have been particularly interesting since no other biosensor device has been reported in literature. In comparison with other biosensors using laccase from the same native source our biosensor has been characterized by larger linear ranges, significant sensitivities and good LODs. To challenge our biosensor with real samples, tap water samples spiked with known amount of catechol and resorcinol have been employed. This article is protected by copyright. All rights reserved