Tag Archive for: SAW

Tracking Recovery

Tracking Recovery Technology Note

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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.

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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.

Carbaryl Biosensor based on antibody detection

Biosensor Application Note

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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) …

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Comparison between High Fundamental Frequency Quartz Crystal Microbalance and Love Mode Surface Acoustic Wave devices in the detection of Carbaryl pesticide

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Authors: J.V. García, M.I. Rocha, C. March, P. García, L.A. Francis, A. Montoya, A. Arnau, Y. Jiménez

Event: Acoustic Sensors in analytical and Biophysical Studies, 29-30 August 2013, IMBB-FORTH, Heraklion, Crete.

 

In this work two acoustic technologies: High Fundamental Frequency Quartz Crystal Microbalance (HFF-QCM) and Love Mode Surface Acoustic Wave (LM-SAW) have been compared for the detection of Low Molecular Weight (LMW) compounds in terms of Sensitivity and LOD. The results have also been compared with those obtained with other techniques: Traditional QCM, Surface Plasmon Resonance (SPR) and Enzyme-Linked ImmunoSorbent Assay (ELISA). Carbaryl pesticide was chosen as model analyte because it had been used as a reference LMW compound by those mentioned techniques.

AWS-A10 research platform (AWSensors, Spain) was used to perform the experiments. This platform allowed for a comparison of both devices measured by the same characterization system under similar experimental conditions.

The results achieved with LM-SAW and 100Mhz HFF-QCM were in the same order of magnitude. The achieved value sensitivity (I50 value) and LOD (I90 ) were around 0.31 µ/L and 0.09 µ/L, respectively, for LM-SAW device, and around 0’66 µ/L and 0’14 µ/L, respectively, for HFF-QCM device. Sensitivities and LODs with these novel developments on acoustic technologies improve SPR and traditional QCM technologies, and approach ELISA’s ones.

Review the poster about this experiment by clicking here:

Póster about AWS-HFF sensors for detection of Carbaryl pesticide showed at Crete 2013