Determinación de herbicidas nitrofenoles y s-triazinas por voltamperometría de adsorción-redisolución

En este trabajo se han desarrollado métodos para determinar los herbicidas dinoseb, metoprotrina y terbutrina empleando polarografía diferencial de impulsos (dpp) y voltamperometria de adsorción-redisolución (adsv). A partir del comportamiento polarográfico de los tres herbicidas se han establecido las caracteristicas del proceso electrodo proponiéndose los mecanismos de reducción correspondientes y métodos para su determinación mediante dpp que se han aplicado para determinar dinoseb en manzanas y metoprotrina y terbutrina en peras. Tras verificar la posibilidad de utilizar la adsorción como etapa de preconcentración efectiva, se han desarrollado métodos adsv para determinar los tres herbicidas sobre el electrodo de gota colgante de mercurio (hmde). Se han establecido sus caracteristicas analíticas y se han aplicado a la determinación de dinoseb en manzanas y zumo de manzana y de metoprotrina y terbutrina individualmente en aguas potables y procedentes de riego. Asimismo, se ha desarrollado un método para determinar dinoseb por adsv sobre el electrodo de película de mercurio, mejorando el límite de determinación del orden de 10 veces con respecto al obtenido sobre el hmde. Este método se ha aplicado a la determinación del herbicida en muestras de zumo de manzana. Finalmente, se ha evaluado la posibilidad de aplicar la técnica adsv en medios dispersos. Determinando terbutrina en medio micelar formado con pentanosulfonato sódico y en medio emulsionado constituido con acetato de etilo se han obtenido limites de determinación del mismo orden que en disoluciones acuosas.Depto. de Química AnalíticaFac. de Ciencias QuímicasTRUEpu

Non-Invasive Breast Cancer Diagnosis through Electrochemical Biosensing at Different Molecular Levels

The rapid and accurate determination of specific circulating biomarkers at different molecular levels with non- or minimally invasive methods constitutes a major challenge to improve the breast cancer outcomes and life quality of patients. In this field, electrochemical biosensors have demonstrated to be promising alternatives against more complex conventional strategies to perform fast, accurate and on-site determination of circulating biomarkers at low concentrations in minimally treated body fluids. In this article, after discussing briefly the relevance and current challenges associated with the determination of breast cancer circulating biomarkers, an updated overview of the electrochemical affinity biosensing strategies emerged in the last 5 years for this purpose is provided highlighting the great potentiality of these methodologies. After critically discussing the most interesting features of the electrochemical strategies reported so far for the single or multiplexed determination of such biomarkers with demonstrated applicability in liquid biopsy analysis, existing challenges still to be addressed and future directions in this field will be pointed out

Empowering Electrochemical Biosensing through Nanostructured or Multifunctional Nucleic Acid or Peptide Biomaterials

Electrochemical biosensors continue to evolve at an astonishing pace, consolidating as competitive tools for determining a wide range of targets and relentlessly strengthening their attributes in terms of sensitivity, selectivity, simplicity, response time, and antifouling ability, making them suitable for getting a foothold in real-world applications. The design and exploitation of nanostructured or multifunctional nucleic acid or peptide biomaterials is playing a determinant role in these achievements. With the aim of highlighting the potential and opportunities of these biomaterials, this perspective article critically discusses and overviews the electrochemical biosensors reported since 2019 involving nanostructured and multifunctional DNA biomaterials, multifunctional aptamers, modern peptides, and CRISPR/Cas systems. The use of these biomaterials as recognition elements, electrode modifiers (acting as linkers or creating scaffolds with antifouling properties), enzyme substrates, and labeling/carrier agents for signal amplification is discussed through rationally and strategically selected examples, concluding with a personal perspective about the challenges to be faced and future lines of action

Affinity-Based Wearable Electrochemical Biosensors: Natural versus Biomimetic Receptors

This review delves into the titanic research efforts carried out during the last years on affinity-based wearable electrochemical biosensors, using both natural (antibodies) and biomimetic (aptamers, peptides and molecular imprinted polymers) receptors. The rationale and application of selected representative strategies is critically discussed, ending with realistic and futuristic visions of the technical barriers, challenges and prospects in the development and adoption of these biodevices in daily routines to ensure well-being against known, unknown and unexpected threats

Electrochemical sensor for rapid determination of fibroblast growth factor receptor 4 in raw cancer cell lysates

The first electrochemical immunosensor for the determination of fibroblast growth factor receptor 4 (FGFR4) biomarker is reported in this work. The biosensor involves a sandwich configuration with covalent immobilization of a specific capture antibody onto activated carboxylic-modified magnetic microcarriers (HOOC-MBs) and amperometric detection at disposable carbon screen-printed electrodes (SPCEs). The biosensor exhibits a great analytical performance regarding selectivity for the target protein and a low LOD of 48.2 pg mL-1. The electrochemical platform was successfully applied for the determination of FGFR4 in different cancer cell lysates without any apparent matrix effect after a simple sample dilution and using only 2.5 μg of the raw lysate. Comparison of the results with those provided by a commercial ELISA kit shows competitive advantages by using the developed immunosensor in terms of simplicity, analysis time, and portability and cost-affordability of the required instrumentation for the accurate determination of FGFR4 in cell lysates

First bioelectronic immunoplatform for quantitative secretomic analysis of total and metastasis-driven glycosylated haptoglobin

The glycosylation status of proteins is increasingly used as biomarker to improve the reliability in the diagnosis and prognosis of diseases as relevant as cancer. This feeds the need for tools that allow its simple and reliable analysis and are compatible with applicability in the clinic. With this objective in mind, this work reports the first bioelectronic immunoplatforms described to date for the determination of glycosylated haptoglobin (Hp) and the simultaneous determination of total and glycosylated Hp. The bioelectronic immunoplatform is based on the implementation of non-competitive bioassays using two different antibodies or an antibody and a lectin on the surface of commercial magnetic microcarriers. The resulting bioconjugates are labeled with the horseradish peroxidase (HRP) enzyme, and after their magnetic capture on disposable electroplatforms, the amperometric transduction using the H2O2/hydroquinone (HQ) system allows the single or multiple detection. The developed immunoplatform achieves limits of detection (LODs) of 0.07 and 0.46 ng mL-1 for total and glycosylated Hp in buffer solution, respectively. The immunoplatform allows accurate determination using simple and relatively short protocols (approx. 75 min) of total and glycosylated Hp in the secretomes of in vitro-cultured colorectal cancer (CRC) cells with different metastatic potentials, which is not feasible, due to lack of sensitivity, by means of some commercial ELISA kits and Western blot methodology.Funding Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Spanish Ministerio de Ciencia e Innovación (PID2019-103899RB-I00 and RTI2018-095756-B-I00), AES-ISCIII Program co-founded by FEDER funds (PI17CIII/00045 and PI20CIII/00019 grants), TRANSNANOAVANSENS-CM Program from the Comunidad de Madrid (Grant S2018/NMT-4349).S

Aplicación de herramientas telemáticas para la mejora de la calidad docente del programa interuniversitario de la experiencia de la Universidad de Salamanca

Memoria ID-0047. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2009-2010.El proyecto se ha basado en un objetivo global a través del cual se pretendía la integración social y adaptación del colectivo de estudiantes mayores a la evolución social, económica y tecnológica del momento, para que conozcan, utilicen y comprendan las posibilidades de enseñanza/aprendizaje que les ofrecen las TICs. Esta meta global se ha dividido en dos objetivos operativos: 1. Abrir al alumnado adulto las posibilidades del aprendizaje virtual, formándoles para el uso y la participación en la plataforma telemática donde se encuentran a su disposición los materiales de las asignaturas y cursos. 2. Facilitar a los estudiantes mayores el acceso a cursos, contenidos y materias regladas de la Universidad de Salamanca, pudiendo así aspirar a una formación universitaria más allá del Programa de la Experiencia

Biosensing and Delivery of Nucleic Acids Involving Selected Well-Known and Rising Star Functional Nanomaterials

In the last fifteen years, the nucleic acid biosensors and delivery area has seen a breakthrough due to the interrelation between the recognition of nucleic acid’s high specificity, the great sensitivity of electrochemical and optical transduction and the unprecedented opportunities imparted by nanotechnology. Advances in this area have demonstrated that the assembly of nanoscaled materials allows the performance enhancement, particularly in terms of sensitivity and response time, of functional nucleic acids’ biosensing and delivery to a level suitable for the construction of point-of-care diagnostic tools. Consequently, this has propelled detection methods using nanomaterials to the vanguard of the biosensing and delivery research fields. This review overviews the striking advancement in functional nanomaterials’ assisted biosensing and delivery of nucleic acids. We highlight the advantages demonstrated by selected well-known and rising star functional nanomaterials (metallic, magnetic and Janus nanomaterials) focusing on the literature produced in the past five years

Opportunities, Challenges, and Prospects in Electrochemical Biosensing of Circulating Tumor DNA and its Specific Features

Nowadays, analyzing circulating tumor DNA (ctDNA), a very small part of circulating free DNA (cfDNA) carried by blood, is considered to be an interesting alternative to conventional single-site tumor tissue biopsies, both to assess tumor burden and provide a more comprehensive snapshot of the time-related and spatial heterogeneity of cancer genetic/epigenetic scenery. The determination of ctDNA and/or mapping its characteristic features, including tumor-specific mutations, chromosomal aberrations, microsatellite alterations, and epigenetic changes, are minimally invasive, powerful and credible biomarkers for early diagnosis, follow-up, prediction of therapy response/resistance, relapse monitoring, and tracking the rise of new mutant subclones, leading to improved cancer outcomes This review provides an outline of advances published in the last five years in electrochemical biosensing of ctDNA and surrogate markers. It emphasizes those strategies that have been successfully applied to real clinical samples. It highlights the unique opportunities they offer to shift the focus of cancer patient management methods from actual decision making, based on clinic-pathological features, to biomarker-driven treatment strategies, based on genotypes and customized targeted therapies. Also highlighted are the unmet hurdles and future key points to guide these devices in the development of liquid biopsy cornerstone tools in routine clinical practice for the diagnosis, prognosis, and therapy response monitoring in cancer patients

First bioelectronic immunoplatform for quantitative secretomic analysis of total and metastasis-driven glycosylated haptoglobin

The glycosylation status of proteins is increasingly used as biomarker to improve the reliability in the diagnosis and prognosis of diseases as relevant as cancer. This feeds the need for tools that allow its simple and reliable analysis and are compatible with applicability in the clinic. With this objective in mind, this work reports the frst bioelectronic immunoplatforms described to date for the determination of glycosylated haptoglobin (Hp) and the simultaneous determination of total and glycosylated Hp. The bioelectronic immunoplatform is based on the implementation of non-competitive bioassays using two diferent antibodies or an antibody and a lectin on the surface of commercial magnetic microcarriers. The resulting bioconjugates are labeled with the horseradish peroxidase (HRP) enzyme, and after their magnetic capture on disposable electroplatforms, the amperometric transduction using the H2O2/hydroquinone (HQ) system allows the single or multiple detection. The developed immunoplatform achieves limits of detection (LODs) of 0.07 and 0.46 ng mL−1 for total and glycosylated Hp in bufer solution, respectively. The immunoplatform allows accurate determination using simple and relatively short protocols (approx. 75 min) of total and glycosylated Hp in the secretomes of in vitro–cultured colorectal cancer (CRC) cells with diferent metastatic potentials, which is not feasible, due to lack of sensitivity, by means of some commercial ELISA kits and Western blot methodology