Suchergebnisse

This work has been supported by the FC15-GRUPIN-021 project from the Asturias Regional Government and CTQ2014-58826-R project from the Spanish Ministry of Economy and Competitiveness (MINECO).

This paper describes the effect ofthe modification of microchip microchannels with two different cationic surfactants on the electrochemical behavior of ferrocene carboxylic acid (FCA), common redoxprobe in bioanalysis. Cetyltrimethylammonium bromide (CTAB), a single-chain surfactant, and didecyldimethylammonium bromide (DDAB), double-chained, were evaluated. The purpose was to obtain a reversal of the electroosmotic flow for allowing precise determination of FCA, an anionic probe that is employed in electrochemical bioassays. Although this was possible in both cases, modification of the microchannel with a high concentration of CTAB produced a differentiation between the free CTAB fraction and the CTAB-combined FCA. DDAB is presented as a good alternative for this modification because this doublechained cationic surfactant forms a more stable quasi-permanent coating on the microchannel surface, avoiding these surfactant-probe interactions. Linear relationship was found between the analytical signal and the concentration of FCA (evaluated between 10 and 150 M) for a modification with 0.1 mM of DDAB ; This work has been supported by MICINN under projects CTQ2011-25814 and by the Asturias Government with funds from PCTI 2006–2009, cofunded with FEDER funds (Programa Operativo FEDER del Principado de Asturias 2007–2013) under project FC-11-PC10-30

This work has been supported by the FC-15-GRUPIN14-021 project from the Asturias Regional Government and the CTQ2014- 58826-R project from the Spanish Ministry of Economy and Competitiveness (MINECO, Spain)

This work has been supported by the FC15-GRUPIN-021 project from the Asturias Regional Government and the CTQ2014-58826-R and MAT2017-84959-C2-1-R projects from the Spanish Ministry of Economy and Competitiveness (MINECO). Andrea Gonzalez-López thanks the Consejería del Principado de Asturias for the award of her Severo Ochoa grant (BP17-36).

This lab experiment describes a complete method to fabricate an enzymatic glucose electroanalytical biosensor by students. Using miniaturized and disposable screen-printed electrodes (SPEs), students learn how to use them as transducers and understand the importance SPEs have acquired in sensor development during the last years. Students can also revise concepts related to enzymatic assays, with glucose oxidase and horseradish peroxidase involved in subsequent reactions. Moreover, they learn the trends that current analytical chemistry follows presently such as miniaturization, portability, and low cost. At the same time, this experiment serves to teach basic analytical concepts (accuracy, precision, sensitivity, and selectivity) in a practical way. The high clinical interest of glucose, due to a large number of diabetes patients around the world, and the application of the sensor to analysis of real food samples make this experiment very attractive to students. The questions set out along this experiment help students to acquire skills for solving analytical problems from the very beginning. ; This work was supported by the FC-15-GRUPIN-021 Project from the Asturias Regional Government and the CTQ2014- 58826-R Project from the Spanish Ministry of Economy and Competitiveness (MINECO).

This work has been supported by the FC15-GRUPIN-021 project from the Asturias Regional Government and the CTQ2014-58826-R project from the Spanish Ministry of Economy and Competitiveness (MINECO)

This work has been supported by the CTQ2014‐58826‐R project from the Spanish Ministry of Economy and Competitiveness (MINECO) and the FC‐15‐GRUPIN14‐021 project form the Asturias Regional Government. P.I. Nanni thanks CONICET for her predoctoral grant. Authors thank to Dr. Oliveira Rodríguez for performing the ELISA with optical detection for anti‐tTG determination.

This research was funded by Italian Government in the framework of PRIN 2017, Prot. 2017YER72 K_005. O. Amor-Gutiérrez thanks the University of Oviedo for the award of the grants "Ayudas para la realización de tesis doctorales" (PAPI-18-PF-13) and "Ayudas económicas de movilidad de excelencia para docentes e investigadores", funded by Banco Santander. A. de la Escosura-Muñiz acknowledges the Spanish Ministry of Science and Innovation MICINN (Spain) for the "Ramón y Cajal" Research Fellow (RyC-2016-20299).

Water Energy NEXUS Conference (2nd. 2018. Salerno, Italy) ; This work was also supported by the EU and FCT (project FOODnanoHEALTH, Portugal 2020, Norte-01-0145-FEDER-000011) and by the Spanish Ministry of Economy and Competitiveness (MINECO, project CTQ2014-58826-R and EUIN2017-86902). Estefanía Costa-Rama also thanks to the Government of Principado de Asturias and Marie Curie-Cofund Actions for the post-doctoral grant "Clarín-Cofund" ACA17-20.

In this work, we report a simple and yet efficient stencil-printed electrochemical platform that can be integrated into the caps of sample containers and thus, allows in-field quantification of Cd(II) and Pb(II) in river water samples. The device exploits the low-cost features of carbon (as electrode material) and paper/polyester transparency sheets (as substrate). Electrochemical analysis of the working electrodes prepared on different substrates (polyester transparency sheets, chromatographic, tracing and office papers) with hexaammineruthenium(III) showed that their electroactive area and electron transfer kinetics are highly affected by the porosity of the material. Electrodes prepared on transparency substrates showed the best electroanalytical performance for the simultaneous determination of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry. Interestingly, the temperature and time at which the carbon ink was cured had significant effect on the electrochemical response, especially the capacitive current. The amount of Cd and Pb on the electrode surface can be increased about 20% by in situ electrodeposition of bismuth. The electrochemical platform showed a linear range comprised between 1 and 200 mg/L for both metals, sensitivity of analysis of 0.22 and 0.087 mA/ppb and limits of detection of 0.2 and 0.3 mg/L for Cd(II) and Pb(II), respectively. The analysis of river water samples was done directly in the container where the sample was collected, which simplifies the procedure and approaches field analysis. The developed point-of-need detection system allowed simultaneous determination of Cd(II) and Pb(II) in those samples using the standard addition method with precise and accurate results ; This work has been supported by the FC-15-GRUPIN-021 project from the Asturias Regional Government and the CTQ2014-58826-R project from the Spanish Ministry of Economy and Competitiveness (MINECO). Daniel Martín-Yerga thanks the MINECO for the award of a FPI grant (BES-2012-054408). Isabel Alvarez-Martos ...

Disposable sensors are low-cost and easy-to-use sensing devices intended for short-term or rapid single-point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource-limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo- and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low-cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities.