Desarrollo de plataformas biosensoras electroquímicas para la detección de marcadores inflamatorios y de cáncer de mama

En la actualidad, el diagnóstico clínico demanda la implementación de metodologías de manejo sencillo, coste asequible, reducido tiempo de respuesta y con capacidad de multiplexado que puedan implementarse en la rutina clínica para la determinación de biomarcadores de relevancia en muestras no invasivas, como biopsias líquidas. En respuesta a estas demandas, en esta Tesis Doctoral se ha abordado el desarrollo de varias plataformas biosensoras electroanalíticas aplicables a la determinación de biomarcadores de inflamación y asociados a cáncer de mama. El funcionamiento de la mayoría de estas bioplataformas se basa en la realización de reacciones de inmunoreconocimiento sobre la superficie de micropartículas magnéticas comerciales. Tras su completa modificación, se acoplan sobre electrodos desechables para realizar la transducción amperométrica, cuya magnitud resulta proporcional a la concentración del biomarcador en estudio..

Systematic Approach to the Synthesis of Cobalt-Containing Polyoxometalates for Their Application as Energy Storage Materials

New energy storage materials are an object of study within the framework of the global energy transition. The development of renewable sources is being boosted thanks to stationary energy storage systems such as redox flow batteries (RFBs). This work reports the synthesis of the cobalt-containing Keggin-type polyoxometalates [CoW12O40]6− (CoW12) and [Co(H2O)SiW11O39]6− (CoSiW11), which have previously been shown to have applicability in RFBs. These procedures were reassessed to meet the strict requirements associated with the further implementation of RFBs, including fast and affordable synthetic procedures with high reaction yields. In contrast to the lengthy and complicated synthetic approaches published to date, the optimized synthesis reported in this work enables the isolation of the pure crystalline salt of the CoW12 anion with a 75% reduction of the time of the whole reaction procedure, eliminating tedious steps such as the recrystallization and including a 20% increased yield. The control of the stoichiometry, fine-tuning of reaction conditions, and the identification of intermediate species, as well as the acidic equilibria taking place during the process, were monitored via thermal, spectroscopic, and structural analyses. In the case of the CoSiW11 anion, its preparation was based on a simple and highly efficient procedure. Moreover, promising electrochemical properties were observed with the use of the one-pot synthetic approach, in which the stoichiometric amounts of the starting reagents are dissolved in the supporting electrolyte to be directly implemented as the electrolyte for a RFB.This work was developed within the framework of the Almagrid project, CER-20191006 funded by Centro para el Desarrollo Tecnológico y la innovación (CDTI). Call for proposals: Accreditation and granting of aid for technological centers of excellence “Cervera”. In addition, this research was funded by the Basque Government within the framework of ‘Research on complementary energy storage technologies, and its combination in efficient and competitive systems for its stationary application in the grid’ project, grant number KK-2022/00043.B.A. and J.G.Z. thank Eusko Jaurlaritza/Gobierno Vasco for funding (grant IT1722-22)

Design and 3D printing of an electrochemical sensor for Listeria monocytogenes detection based on loop mediated isothermal amplification

The aim of this work is the design and 3D printing of a new electrochemical sensor for the detection of Listeria monocytogenes based on loop mediated isothermal amplification (LAMP). The food related diseases involve a serious health issue all over the world. Listeria monocytogenes is one of the major problems of contaminated food, this pathogen causes a disease called listeriosis with a high rate of hospitalization and mortality. Having a fast, sensitive and specific detection method for food quality control is a must in the food industry to avoid the presence of this pathogen in the food chain (raw materials, facilities and products). A point-of-care biosensor based in LAMP and electrochemical detection is one of the best options to detect the bacteria on site and in a very short period of time. With the numerical analysis of different geometries and flow rates during sample injection in order to avoid bubbles, an optimized design of the microfluidic biosensor chamber was selected for 3D-printing and experimental analysis. For the electrochemical detection, a novel custom gold concentric-3-electrode consisting in a working electrode, reference electrode and a counter electrode was designed and placed in the bottom of the chamber. The LAMP reaction was optimized specifically for a primers set with a limit of detection of 1.25 pg of genomic DNA per reaction and 100% specific for detecting all 12 Listeria monocytogenes serotypes and no other Listeria species or food-related bacteria. The methylene blue redox-active molecule was tested as the electrochemical transducer and shown to be compatible with the LAMP reaction and very clearly distinguished negative from positive food samples when the reaction is measured at the end-point inside the biosensor.Garbiñe Olabarria as supported by Ekonomiaren Garapen eta Lehiakortasun Saila, Eusko Jaurlaritza [KK-2021/00082]. M. Mounir Bou-Ali was supported by Eusko Jaurlaritza [Research Group Program, IT1505-22]

Electrochemical Evaluation of Different Graphite Felt Electrode Treatments in Full Vanadium Redox Flow Batteries

The use of flow batteries for energy storage has attracted considerable attention with the increased use of renewable resources. It is well known that the performance of a flow battery depends, among other factors, on the properties of the electrodes, which are generally composed of graphite felt (GF). In this work, thermal, chemical and plasma treatments have been employed to modify the surface of the graphite felt to improve the electrochemical activity of the redox flow cell. The influence of the variables of each of these processes on the generation of surface functional groups and on changes in the obtained surface area have been examined. In this work, the kinetics of redox reactions relevant to the VO2+/VO2+ reaction have been studied with these treated electrodes and the relationship between the nature of the surface and electrochemical activity of the GF is discussed. As a result, an enhanced electrochemical performance (reduction over 200 mV of the separation between anodic and cathodic peaks and 110 mV of the onset potential) in comparison to the untreated GF is obtained for those GF treatments with low oxygenated groups concentration