Scientific publication

High Frequency (100, 150 MHz) Quartz Crystal Microbalance (QCM) Piezoelectric Genosensor for the Determination of the Escherichia coli O157 rfbE Gene

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Authors: Kaory Barrientos, María Isabel Rocha, Marisol Jaramillo and Neil Aldrín Vásquez.
Journal: Analytical Letters (2022)

 

Abstract

Escherichia coli O157 (E. coli O157) is responsible for outbreaks of high morbidity in food-borne infections. The development of sensitive, reliable, and selective detection systems is of great importance in food safety. In this work, two high fundamental frequency (HFF) piezoelectric genosensors (100 and 150 MHz) were designed and validated for the rfbE gene detection, which encodes O-antigen in E. coli O157. HFF resonators offer improved sensitivity, small sample volumes, and the possibility of integration into lab-on-a-chip devices, but their sensing capabilities have not yet been fully explored. This HFF-QCM genosensor uses the method of physisorption based on the union between the streptavidin and the biotin to immobilize the genetic bioreceptor on the surface and detect its hybridization with the target sequence. Parameters such as molecular coating, specificity, and variability were tested to enhance its performance. Although both genosensors evaluated are able to determine the target, the 100 MHz device has a higher response to the analyte than the 150 MHz platform. This is the first step in the development of an HFF-QCM genosensor that may be used as a trial test of E. coli O157 in large batches of samples.

 

You may read the full paper here.

AWSensors, participante en el Programa Xpande 2022

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30/03/2022. Advanced Wave Sensors S.L. (AWSensors) continúa trabajando en su estrategia de internacionalización. Durante los próximos meses, contaremos con el apoyo de un asesor especializado de la Cámara de Comercio de Valencia, en el marco del Programa Xpande 2022, para la elaboración de un Plan de Internacionalización encaminado a abrir nuevos mercados donde comercializar nuestros equipos de instrumentación de sensores acústicos (Quartz Crystal Microbalance with Dissipation monitoring, QCMD, de sus siglas en inglés), así como mejorar la competitividad global.

AWSensors ha sido beneficiaria del Fondo Europeo de Desarrollo Regional cuyo objetivo es mejorar la competitividad de las Pymes y gracias al cual ha puesto en marcha un Plan de Internacionalización con el objetivo de mejorar su posicionamiento competitivo en el exterior durante el año 2022. Para ello ha contado con el apoyo del Programa XPANDE de la Cámara de Comercio de Valencia.

Una manera de hacer Europa

 

Cámara-Comercio-España

Cámara-Comercio-Valencia

Internacionalización-Valencia

Publication on AWSensors technology

Interfacial charge storage mechanisms of composite electrodes based on poly(ortho-phenylenediamine)/carbon nanotubes via advanced electrogravimetry

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Authors: El Mahdi Halim, Rezan Demir-Cakan, Hubert Perrot, Mama El Rhazi, Ozlem Sel

Journal: The Journal of Chemical Physics (2022)

 

Abstract

To reach a deeper understanding of the charge storage mechanisms of electrode materials is one of the challenges toward improving their energy storage performance. Herein, we investigate the interfacial ion exchange of a composite electrode made of carbon nanotube/poly( ortho-phenylenediamine) (CNT/P oPD) in a 1M NaCl aqueous electrolyte via advanced electrogravimetric analyses based on electrochemical quartz crystal microbalance (EQCM). Classical EQCM at different scan rates of the potential revealed the complex electrogravimetric behavior likely due to multi-species participation at different temporal scales. Thereafter, in order to better understand the behavior of each species (ions, counter ions, and co-ions) in the charge compensation mechanism, the electrogravimetric impedance spectroscopy analysis (also called ac-electrogravimetry) was pursued. Ac-electrogravimetry revealed the role of each species where Na + cations and Cl − anions as well as protons participate in the charge compensation mechanism of the CNT/P oPD composite with different kinetics and proportions. The water molecules with opposite flux direction with the cations are also detected, suggesting their exclusion during cationic species transfer. Having analyzed ac-electrogravimetry responses in depth, the synergistic interaction between the CNT and P oPD is highlighted, revealing the improved accessibility of species to new sites in the composite.

 

You may read the full paper here.

Scientific publication

Interface evolution and performance degradation in LiCoO2 composite battery electrodes monitored by advanced EQCM

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Authors: Wanli Gao, Christel Laberty-Robert, Natacha Krins, Catherine Debiemme-Chouvya, Hubert Perrot and Ozlem Sel.
Journal: Electrochimica Acta (2022)

 

Abstract

Unravelling the underlying reasons for degradation mechanism of battery materials is of great fundamental and practical importance. For a classical electrode consisting of an active material, a conductive additive, and a polymeric binder, its capacity fading is commonly related with (i) mechanical degradation of polymeric binder and/or (ii) structural and compositional degradation of active materials. The former is more relevant for electrodes showing volume expansion and represented by the progressive breakage of polymeric binder network during battery operation, leading to the dissolution of the other two components into electrolytes. The latter is generally reflected by an irreversible phase transition in active materials, which may affect the species exchanged at the electrode/electrolyte interface and their interfacial transfer dynamics. By employing a coupled methodology pairing electrochemical techniques with piezoelectric probes derived from quartz crystal microbalance (QCM), this work reports on the evolution of the interfacial processes during electrochemical cycling and correlates to the performance degradation of the electrodes. Shown on a LiCoO2 (LCO) composite electrode as a model system, it was revealed that bare Li+ without a hydration sheath plays a dominant role in charge balance irrespective of the aging degree of the electrode under the experimental conditions of this work. However, Li+ transfer is closely accompanied with free H2O molecules with a Li+:H2O ratio around 10:1 at a polarization state close to LCO redox potential (0.65 V vs. Ag/AgCl). This ratio persists in all cycled electrodes with gradually faded interfacial transfer kinetics of Li+ and H2O along cycling. Such a fading in species interfacial transfer kinetics driven by the surficial evolution from LiCoO2 to CoO plays a major role in the electrode performance degradation during cycling.

LiCoO2 composite battery electrodes

You may read the full paper here.

The difference the “D” makes in QCMD

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AWSensors presents a new Technology Note on the importance of dissipation measuring when working with QCMD: “The difference the “D” makes in QCMD”.

Dissipation

What is dissipation, and why it is useful?

Quartz Crystal Microbalance with Dissipation, or QCMD, is having a tremendous impact on research in the soft and biological interfaces fields because of its versatility and the wealth of information it provides. In this Technology Note, we discuss the origins of dissipation in the different systems studied by QCMD, from complex fluids and polymer films to biomolecular and particle assemblies, and the information dissipation can provide, from characterizing viscoelasticity to studying molecular conformation.

In this Technical Note we discuss the origins of dissipation, how it can be used to verify the applicability of the Sauerbrey relationship and their interaction with the viscoelasticity and in the biological sensing.

 

Download the Full Technology Note

You can read and download the full Technology Note in pdf file from this link. A list of our Technology Notes can be found on our Technology Web Page..

 

 

Scientific publication

Ion Dynamics at the Carbon Electrode/Electrolyte Interface: Influence of Carbon Nanotubes Types

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Authors: Freddy Escobar-Teran, Hubert Perrot and Ozlem Sel.
Journal: Materials (2022)

 

Abstract

Electrochemical quartz crystal microbalance (EQCM) and AC-electrogravimetry methods were employed to study ion dynamics in carbon nanotube base electrodes in NaCl aqueous electrolyte. Two types of carbon nanotubes, Double Wall Carbon Nanotube (DWCNT) and Multi Wall Carbon Nanotube (MWCNT), were chosen due to their variable morphology of pores and structure properties. The effect of pore morphology/structure on the capacitive charge storage mechanisms demonstrated that DWCNT base electrodes are the best candidates for energy storage applications in terms of current variation and specific surface area. Furthermore, the mass change obtained via EQCM showed that DWCNT films is 1.5 times greater than MWCNT films in the same potential range. In this way, the permselectivity of DWCNT films showed cation exchange preference at cathode potentials while MWCNT films showed anion exchange preference at anode potentials. The relative concentration obtained from AC-electrogravimetry confirm that DWCNT base electrodes are the best candidates for charge storage capacity electrodes, since they can accommodate higher concentration of charged species than MWCNT base electrodes.

You may read the full paper here.

Scientific publication

Synthesis and covalent immobilization of redox-active metallopolymers for organic phase electrochemistry

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Authors: Hanna Hübner, Riccardo Candeago, Deborah Schmitt, Alexander Schießer, Beichen Xiong, Markus Gallei and Xiao Su.
Journal: Polymer (2022) 244, 124656.

 

Abstract

Redox-active metallopolymers are promising stimuli-responsive platforms for a range of applications including sensing, energy storage, and selective separations. In particular, heterogeneously-functionalized metallopolymers can modulate the capture and release of target molecules, driven by redox electron-transfer. However, prior metallopolymer-functionalized electrodes have been fabricated by non-covalent methods, and tailored for aqueous phase applications. As such, despite the existing potential for heterogeneous applications in organic phase, there are significant constraints to the stability of metallopolymers in organic solvents, including high solubility in solvents such as chloroform or tetrahydrofuran. We propose the immobilization of thiol-functionalized redox-active metallopolymers on metallic surfaces as a facile way to enhance stability and cyclability in organic media, and thus broaden the applicability of redox-metallopolymers for organic phase applications. We explore the anionic polymerization of metal-containing monomers vinylferrocene (VFc) and ferrocenyldimethylsilane (FS), and their thiol end-functionalization by living anionic polymerization strategies. PFS and PVFc with molar masses ranging from 1800 to 49900 g mol−1 and 2900 to 6300 g mol−1 respectively were prepared with a segment of poly(ethylene sulfide), as characterized by size-exclusion chromatography, NMR spectroscopy, MALDI/ToF, thermogravimetry, and elemental analysis. Both metallopolymers were immobilized on gold substrates by a grafting-to protocol, with demonstrated redox-responsiveness by electrochemical control. In the case of immobilized PVFc, operando electrochemical testing demonstrated the stable and reversible electrochemical cycling capabilities (>74% maximum current retained after 100 oxidation/reduction cycles) in several organic solvents including chloroform, tetrahydrofuran, ethanol, methanol, acetonitrile, and acetone. Immobilized PFS was stable in chloroform, with a 83% maximum current retained after 100 oxidation/reduction cycles. We envision future applications of these covalently immobilized metallopolymers for a broad range of fields from selective separations to sensing and energy storage.

 

You may read the full paper here.

Publication on AWSensors technology

Adsorption of organic matter on titanium surfaces with nano- and micro-scale roughness studied with the electrochemical quartz crystal microbalance dissipation technique

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Authors: Claes-Olof A. Olsson, Anna Neus Igual-Muñoz, and Stefano Mischler.

Journal: Biointerphases 2021.

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AWSensors participa en el programa Becas E+E de IVACE

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Siguiendo con la estrategia de internacionalización de AWSensors, la empresa incorpora a Nuria Portolés Cervera al equipo de Ventas y Marketing dentro del marco de su participación en el programa de Becas E+E – Exportación y Empleo 2021 del Instituto Valenciano de Competitividad Empresarial (IVACE). Durante 8 meses, Nuria cumplirá con un plan formativo en Comercio Exterior y contribuirá con su trabajo en la internacionalización y promoción de la marca y productos QCMD de AWSensors a nivel internacional.

El pasado 28 de diciembre de 2021 se otorgaron los destinos donde las personas becadas en este programa, como Nuria, realizan su formación práctica. Este acto institucional, que estuvo presidido por el Molt Honorable Sr. Ximo Puig, Presidente de la Generalitat Valenciana, y por el Conseller de Economía Sostenible, Sectores Productivos, Comercio y Trabajo, el Sr. Rafael Climent, tuvo lugar en el Palau de la Generalitat.

Nuria Portolés

El programa de Becas E+E está gestionado por IVACE y financiado por el Fondo Social Europeo, dentro de la Iniciativa de empleo juvenil. El programa tiene por objetivo proporcionar una formación profesional en Comercio Exterior a las personas participantes, así como de dotar de más herramientas a las entidades y empresas participantes que sirvan de apoyo en su internacionalización.

 

 

Fuente: https://twitter.com/i/broadcasts/1OdKrBMzpneKX

QCMD workshop training

Hands-on Training Workshop on QCMD at IMBB-FORTH, Greece

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AWSensors ran a successful hands-on training workshop at the Gizeli group at IMBB FORTH in Crete, Greece. Undergraduate students, graduate students, and postdocs were invited to attend the session and learned how to use our X1 QCMD instrument and Love-SAW devices. During the workshop, participants had the opportunity to understand how to effectively utilize these acoustic sensing technologies for their research. Building on their core expertise in molecular biology and biophysics, the Gizeli group is exploring biosensing applications in human, animal, and plant disease diagnostics as well as pathogen and environmental pollutant detection. The training helped researchers in the group exploit the unique advantages of AWSensors’ equipment, such as sensitivity, time resolution, flexibility, integrated flow control, and ease of use, for biosensor development.