Tag Archive for: QCM

Innovative Company

Innovative SME

February 22nd 2021: AWSensors was registered as an innovative company by the Spanish Government on March 26th 2020.

This acknowledgement was granted to AWSensors because it is a company which is developing new products to be introduced in the market and it is improving the existent ones in the QCM market.

The applications were AWSensors technology is being applied are listed in our Application webpage. Visit our Technology webpage to learn more about how AWSensors technology works.

 

Innovative SME - PYME innovadora

Love-SAW sensors

Love-SAW sensors Technology Note

February 15th 2021: AWSensors is pleased to invite you to take a look to the its new Technology Note on Love-SAW sensors “AWSensors Love-SAW sensors“.

Summary of the Note

Advanced Wave Sensors (AWSensors) develops and markets various types of sensors: classical QCM, High Fundamental Frequency QCM, and Love-Surface Acoustic Wave (Love-SAW). Love-SAW sensors do not measure love, but they do measure other interesting properties of interfacial layers. This Note is dedicated to explaining the basics of the operation of these less known acoustic sensors.

 

Love-SAW sensor

Introduction to Love-SAW sensors

Love waves are shear horizontally (SH) polarized surface acoustic waves. They are named after Augustus Edward Hough Love, who predicted them mathematically in 1911, and appear in fields as distinct as seismology and sensing [1].

Figure 1. a) Piezoelectric material, such as quartz, cut at a certain angle relative to the crystallographic axis, is used as a substrate in the construction of the Love-SAW sensors which basic structure is shown in b) (Taken from [2]).

Love-SAW sensors use a piezoelectric substrate (like quartz), in which the surface acoustic waves are excited by applying electrical current in a specific direction relative the crystallographic orientation of the piezoelectric material (see Figure 1a). The waves are then confined into the guiding layer overlaying the piezoelectric substrate. The structure of such a sensor is shown in Figure 1b where the current is applied through the so-called interdigitated transducers (IDTs), located between the substrate and the guiding layer. A standing Love wave is generated in the space between the IDTs (D in Figure 2), defining the sensing area. The condition for the existence of these waves is that the shear velocity in the guiding layer is less than that in the substrate. It is this difference in the mechanical properties between the guiding layer and the substrate that slows down the wave propagation velocity and traps the acoustic energy in the guiding layer keeping the wave energy near the surface. The sensitivity of this device is determined by the degree of wave confinement in the guiding layer. Thus, the higher the confinement of the wave in the guiding layer, the higher the sensitivity of the device is.

Love-SAW sensors typically operate at frequencies of hundreds of MHz. The operating frequency of a Love-SAW sensor is defined by the materials of its structure, the periodicity of the IDTs, λ in Figure 2, and the guiding layer thickness, d [2].

Key advantages of Love-SAW devices include efficient operation in liquids, mechanical stability (robustness), and high sensitivity (due to the high operating frequency by only changing the IDTs periodicity). Key limitations include a need for calibration due to the lack of simple, predictive model describing SAW wave propagation akin to the Sauerbrey relationship in QCMD or Lorentz-Lorenz and de Feijter’s relationships in ellipsometry. [3–5]

Continue reading by downloading the full Technology Note (below) …


Download the Full Technology Note

You can download the full Love-SAW Technology Note in pdf format from this link. A list of our Technology Notes can be found on our Technology Web Page.

Other references about Love-SAW sensors

 

X4 QCMD System

X4 Launching

January 19th 2021: X4 launching

AWSensors is pleased to announce the launching of its new Advanced Multichannel QCMD system, the X4 Instrument, which allows the users to boost their productivity.

X4 Instrument


Visit X4 launching Landing-page

Learn more about this new instrument in its landing page.

QCMD in Lipid Research

QCMD in Lipid Research Tech Note

October 15th 2020: AWSensors is pleased to invite you to take a look to its Technology Note entitled “QCMD in Lipid Research”.

Summary of the Note

QCMD is a label-free surface-analytical technique based on a quartz resonator excited to oscillate at its resonance frequency on one or more overtones. Resonators can have various coatings: gold (Au), silica (SiO2), titania (TiO2), etc. It works in aqueous media or organic solvents and is therefore widely used for studying solid/liquid interfaces. At each overtone, QCMD measures changes in the resonance frequency and energy dissipation due to the processes occurring at the resonator surface. Examples of such processes include formation of a film or changes in the geometrical or physical properties of the film.

The key feature that makes QCMD useful in lipid research is its ability to distinguish between different geometries and topologies of lipidic assemblies at interfaces, for example, homogenous solid-supported bilayers or monolayers vs. adsorbed liposomes or other structures (such as cubosomes) without relying on fluorescent or deuterated labels but by relying on the combination of the frequency and dissipation.

QCMD in Lipid Research

Introduction

Lipid-related QCMD work can be grouped into several topics, with a total of more than a thousand publications:
• Studies focusing on the interactions between lipids and surfaces.
• Studies focusing on the properties of the lipids, such as their phase behavior, adsorbed liposome deformation, etc.
• Studies examining interactions between lipids and membrane-binding proteins, peptides or viruses. Particularly interesting is that QCMD offers a way to study clustering of membrane-bound proteins.
• Studies focusing on the interactions of lipids with polymers or with nanoparticles.

 

Continue reading by downloading the full Technology Note (below) …


Download the Full Technology Note

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.

Tracking Recovery

Tracking Recovery Technology Note

September 15th 2020: AWSensors is pleased to invite you to take a look to its new Technology Note entitled “Tracking Recovery Technology Note”.

Summary of the 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.

Tracking Recovery

Introduction

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.

Continue reading by downloading the full Technology Note (below) …


Download the Full Technology Note

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.

Carbaryl Biosensor based on antibody detection

Biosensor Application Note

July 3rd 2020: AWSensors is pleased to invite you to take a look to the Biosensor Application Note entitled “Acoustic Biosensor“.

Summary of the Note

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.

Biosensor

Introduction

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.

Continue reading by downloading the full Application Note (below) …


Download Full Application Note

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.

QCMD

QCMD New Technology Note

SLB

Lipid Bilayers New Application Note

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“.

Summary of the Note

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. SLB

Introduction

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) …


Download Full Application Note

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.

Liqbiopsens project

AWSENSORS HOSTS THE 24M MEETING OF LIQBIOPSENS EUROPEAN PROJECT

February 1st 2018

AWSensors host the 24-Month Meeting of LIQBIOPSENS EU project

The meeting of all the project partners was held in Valencia, Spain, at the headquarters of AWSensors and Sistemas Genómicos, where significant advances were presented between the project partners and important decisions were taken to successfully continue pursuing the project goals. Another whole year is still required to complete the project.

The consortium for the development of this project is composed of the following institutions: Servicio Andaluz de Salud (Spain), Université Catholique de Louvin (Belgium),  Foundation for Research and Technology Hellas (Greec), DestiNA Genomics (UK, Spain), Sistemas Genómicos (Spain) and AWSensors (Spain). AWSesensor.

If you wish to know more about the LIQBIOPSENS project, visit the project website at http://liqbiopsens.com.