Authors: Román Fernández; María Calero; Ilya Reviakine; José Vicente García; María Isabel Rocha-Gaso; Antonio Arnau; Yolanda Jiménez
Journal: IEEE Sensors Journal, 2020
September 15th 2020: AWSensors is pleased to invite you to take a look to its new Technology Note entitled “Tracking Recovery Technology Note”.
Use of the AWSensors X1 Instrument Tracking Recover feature to monitor overtones frequency and dissipation shifts of air-to-liquid medium exchanges onto 5 MHz QCM sensors.
The Tracking Recovery feature included in AWSensors X1 platform allows the user to monitor large and fast frequency shifts in QCM (Quartz Crystal Microbalance) admittance spectrum. These sudden modifications in the sensor response are common is some applications where dramatical changes in the viscoelastic properties of the sensor surrounding medium take place.
This technical note illustrates the utility of tracking recovery feature to characterize an air-to-liquid medium exchange. According to Kanazawa and Gordon theory predictions [1], a complex frequency shift is expected in the sensor electromechanical response when the semi-infinite medium placed over the QCM’s top electrode is replaced by other semi-infinite medium. This shift will depend on the viscosity and density properties of the final medium. Following, Kanazawa-Gordon equation is presented for both the frequency (Eq. 1) and the half-bandwidth (Eq. 2) shifts.
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You can download the full Note in pdf format through this link. A list of our Technology Notes can be found on our Technology Web Page.
July 3rd 2020: AWSensors is pleased to invite you to take a look to the Biosensor Application Note entitled “Acoustic Biosensor“.
An immunosensor application for determination of carbaryl pesticide was developed by using AWS A20 research platform and AWS F20 Fluidic System. Carbaryl was chosen as the model analyte. Two kinds of acoustic sensors were employed: AWS HFF-QCM sensors (50 MHz and 100 MHz) and Love-SAW sensors with appropriate cells. The AWS A20 platform allowed monitoring phase-shift changes at constant frequency as a function of the sensor surface mass changes.
Sensor functionalization: Carbaryl hapten conjugate was covalently immobilized by means of Self Assembled Monolayer (SAM).
Immunoassay format: The chosen competitive immunoassay was a binding-inhibition test based on conjugate-coated format. Carbaryl analyte competes against the immobilized hapten-conjugate for Monoclonal Antibodies.
Carbaryl detection: Samples were injected onto the sensors’ surfaces. AWS software allowed controlling sample injection and fluidics. Furthermore, the employed platform allowed performing the measurements at a constant temperature of 25°C ± 0.05°C.
Since analyte inhibits antibody binding to its respective immobilized conjugates, increasing concentrations of analyte are detected by a change in the increment of the phase-shift of the sensor. The following figures present a representative assay cycle selected from a continuous monitoring in a carbaryl determination, for 100 MHz HFF QCM and 120MHz Love Wave Sensors.
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You can download the full Application Note in pdf file from this link or download it from our Applications Web Page where you can find this and the rest of our Application and Technology Notes.
Authors: Martin Zalazar; Gabriel Muñoz; Rodrigo M Torres
Journal: Investigative Ophthalmology & Visual Science, 2020
Authors: Jeffrey E. Chen, Qifeng Wang, Kenneth R. Shull, Jeffrey J. Richards
Journal: Journal of Colloid and Interface Science, 2020
May 15h 2020: AWSensors is pleased to announce the release of its new Application Note on Supported Lipid Bilayers (SLB) entitled “Supported Lipid Bilayer formation followed at low- and high-fundamental frequencies“.
The process of supported lipid bilayer (SLB) formation from adsorbed liposomes is a robust biophysical system that is used in laboratories all over the world. Here, it is used to test AWSensors Quartz Crystal Microbalance with Dissipation measurement (QCMD) equipment and high fundamental frequency QCMD sensors. It is shown that the AWSensors QCMD system correctly and quantitatiely reports the frequency and dissipation changes associated with the SLB formation on high- and low-fundamental frequency SiO2-coated sensors. Some differences between the two types of sensors are highlighted. 
Quartz crystal microbalance with dissipation measurement, or QCMD, has become a popular technique for research in such disparate fields as material science, biophysics, electrochemistry, and immunosensing. [1] One of the reasons for the wide range of applicability and popularity of QCMD is its ability to provide information about molecular organization (topology and geometry) at solid/liquid interfaces. Specifically, it was shown how the combination of frequency and dissipation could distinguish between different surface-immobilized lipidic assemblies: adsorbed liposomes and supported lipid bilayers (SLBs; Figure 1).[2] This allowed the process of SLB formation from liposomes on SiO2-coated QCMD sensors to be followed in situ.[2] Subsequent studies further showed how the combination of frequency and dissipation measurements on various overtones could be used to study adsorbed liposome deformation [3,4] and detect mutations through the analysis of DNA conformation and length. [5, 6]
Continue reading downloading the full Application Note (below) …
You can download the full Application Note in pdf file from this link or download it from our Applications Web Page where you can find this and the rest of our Application and Technology Notes.
Authors: Lourdes Cervera- Chiner, Yolanda Jiménez, Ángel Montoya, Marisol Juan-Borrása, Nuria Pascual, Antonio Arnau, Isabel Escriche
Journal: Food Control, 2020
Authors: Marta M. Maciel, Sónia G. Patrício, João Borges, Pavel A. Levkin, Tiago R. Correia, João F. Mano
Journal: European Journal of Inorganic Chemistry, 2020
Authors: Laura Buitrago, Camilo Ortiz, Kaory Barrientos, Marisol Jaramillo
Journal: Biointerface Research in Applied Chemistry, 2020
