Tag Archive for: Acoustic sensing system

The difference the “D” makes in QCMD

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


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.


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Custom AWSensors Sensors

Custom Sensors Technology Note – Custom Coating QCM

September 14th 2021: AWSensors is pleased to invite you to take a look to its new Technology Note entitled “Custom Sensors”.

Custom AWSensors Sensors

Summary of the Note

This Technology Note describes how to use of custom-coated QCMD sensors with AWSensors instruments. AWS Suite software has a Custom Sensor feature that allows the user to add custom-coated sensors to their sensor list and configure their electrical parameters so that the software can perform the search and characterization of the resonance parameters of the sensors during automatic setup.


AWSensors instruments can characterize a wide range of sensors: classical low-frequency (5 MHz to 10 MHz) QCMD, high-frequency (HFF) QCMD, and Love- Surface Acoustic Wave (Love-SAW). Furthermore, an important aspect of the AWSensors QCMD technology is the flexibility the customer has in terms of surface coatings of the QCMD sensors. The AWS Suite software includes the default configurations for many “standard” sensors supplied by us. Moreover, it allows the user to work with custom sensors, where the coating has affected the resonance properties. Some third-party sensors, compatible with the AWSensors measurement cells, may also benefit from this feature.

Up to five custom sensors can be defined by the user by introducing measured resonance properties. This Technical Note provides a description of this feature and a step-by-step guide for its use.

Download the Full Technology Note

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

EQCM cell

Cobalt EQCM Application Note

July 2nd 2021: AWSensors is pleased to invite you to take a look to its Cobalt EQCM Application Note entitled “Cobalt Deposition and Dissolution“.

Cobalt EQCM Application Note

Summary of the Note

Use of AWS A20 RP in combination with a compatible potentiostat to perform an electrochemical study of deposition and dissolution of metallic layers onto the gold electrode of an AWS HFF-QCM sensor.

Materials and Methods


A 100MHz AWS HFF-QCM sensor was used with AWS A20 RP platform in combination with the SP-200 floating mode Potentiostat/Galvanostat from Biologic. The signals associated with the sensor phase monitoring in the AWS A20RP and the current and potential measurement of the SP-200 were monitored. The deposition solution was 10mM K2SO4 + 0.001M KCl + 0.001M H2SO4 + 0.001M (CoSO4)·7H2O solution. A Pt counter electrode was used with a saturated KCl solution Ag/AgCl reference electrode. The working electrode was the grounded electrode of the AWS HFF-QCM sensor.

Cyclic Voltametry:

Determination of the Nernst equilibrium potential and the investigation of the overpotential deposition of Cobalt on the gold electrode of the HFFQCM. The potential was held at –0.4V ten seconds before starting the cyclic voltammetry. A potential scan with a rate of 10mV/s was applied from –0.4 to –1.5V.

Underpotential Deposition:

Controlled deposition of atomic layers of Cobalt on the AWS HFF-QCM sensor.

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 Notes.

Other references

QCMD webinar

QCM-D Webinar

May 24th 2021: AWSensors is pleased to invite you to participate in a QCM-D Scientific Webinar its Distributor Technex, in the BENELUX area, and AWSensors are orginizing. The scientific talk is entitled “Studying Soft Interfaces with Shear Waves: Principles and Applications of the Quartz Crystal Microbalance (QCM-D)” and  will be given by Prof. Diethelm Johannsmann.


QCMD Webinar

QCM-D Webinar details

The webinar will take place on Thursday, June 10th, 2021 from 15:00 to 16:30 hrs and it will be free of charge.

To join us, please register on this link: http://eepurl.com/gDLYUD and we will send you the Webinar details.

Speaker’s Short Biography

Diethelm Johannsmann is Professor of Physical Chemistry and the director of the Physical Chemistry Institute at Clausthal University of Technology, Germany. He has made fundamental contributions to the subject of QCM(D), reflected in more than 150 articles, several book chapters, and books. His model is widely used in the analysis of QCM-D data, and he developed free software for QCM-D data analysis and modelling.  You can find more information about his work on his website, https://www.pc.tu-clausthal.de/en/research/johannsmann-group/prof-dr-diethelm-johannsmann/.


QCMD Immunosensor

New QCMD Immunosensor Application Note

May 20th 2021: AWSensors is pleased to invite you to take a look to its new Immunosensor Application Note entitled “QCMD immunosensor for small molecule analytes“.

Summary of the Note

A QCMD-based immunoassay for label-free analysis of small molecule concentration in industrial samples was developed using an AWS QCMD system with surface-modified 5 MHz fundamental frequency QCMD sensors. Accuracy and precision of the immunoassay is evaluated with respect to the industry-standard HPLC reference.

QCMD Immunosensor


Accurate, rapid, and cost-effective quantification of small molecule analytes is a pressing problem in various industrial (food, agriculture, environmental protection) and health-related fields. Existing approaches include enzyme-linked immunosorbent assays (ELISAs) and various types of chromatography (e.g., High Performance Liquid Chromatography, HPLC). These approaches require trained personal and centralized laboratories, and their deployment in the field is difficult or impossible.

Quartz Crystal Microbalance with Dissipation, or QCMD, is emerging as a promising technology for the development of fast, portable, automated, and cost-effective immunosensors. Here, we demonstrate a competitive small molecule immunoassay based on the AWSensors QCMD technology.

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 Notes.

Other references


Antibody Detection with Quartz Crystal Microbalance

May 10th 2021: AWSensors offers acoustic sensors for antibody detection. Acoustic biosensor-based immunosensing with  High-Fundamental Frequency Quartz Crystal Microbalance (HFF-QCM) and Love-SAW sensors offers several advantages over Enzyme Linked Immuno Assay (ELISA) or Surface Plasmon Resonance (SPR).

Acoustic sensors antibody detection advantages over ELISA

  • Sensitivity approximately as a standard ELISA or better.
  • Acoustic sensors offer label-free detection of the antibody-antigen binding.
  • Full automation.
  • Pre-calibrated (the user does not need to run the standards. More samples can be run. Reduced cost per sample).
  • Speed.
  • Quantitative real-time /in-situ monitoring.
  • Turn-key solution (no need to specialized detection equipment, reader, or spectrophotometer).
  • Reduced complexity, relaxed requirements for trained personnel.
  • Small volumes (~ 10 of ul per sample).
  • Parallelization and multiple analyte detection through sensor arrays.
  • Sensor re-usablity, leading to reduced assay cost.

Acoustic sensors antibody detection advantages over SPR

  • Better sensitivity.
  • QCM also sees solvent.
  • Provides conformational information of the surface film.
  • Miniaturization and integration into portable systems.
  • Easier to develop parallel and multiple analyte assays through sensor arrays.
  • Affordability.

Therefore, one can develop biosensors based on acoustic immunosensors with highly attractive features in order to rapidly detect pathogens like viruses and bacteria [1], and low molecular weigh compounds.

Application Example

Our Biosensor Application Note  is an application example where we describe a sensitive detection of a low molecular weight pesticide carbaryl using competitive immunoassay with hapen-conjugates immobilized on high-fundamental frequency QCMD sensors, SAMs and monoclonal antibodies (MAb) [2, 3]. As a result, we achieved a very sensitive detection of the carbaryl analyte.




[1] Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review 

[2] High-frequency phase shift measurement greatly enhances the sensitivity of QCM immunosensors

[3] Love Wave Immunosensor for the Detection of Carbaryl Pesticide  

Potentiostat Integration for EQCM

Potentiostat Integration Application Note

March 15th 2021: AWSensors is pleased to invite you to take a look to the its new Application Note on Potentiostat Integration entitled “Potentiostat integration with AWSensors equipment“.

Summary of the Note

Seamless integration of QCMD and electrochemistry in the AWSensors EQCMD systems allows simultaneous measurements of the amount, electrochemical properties, and organization of material at the air/liquid interface accessed through the changes in the resonance frequency and dissipation measured by QCMD and the potential/current relationships measured with an integrated potentiostat or a galvanostat. The capabilities of the integrated AWSensors electrochemical EQCMD systems are illustrated here using the electropolymerization of aniline as an example.

Potentiostat Integration for EQCM


Investigation of complex interfacial processes benefit from combinations of complementary surface-analytical techniques that are based on different principles and approach the interface from complementary perspectives. [1,2] In this regard, the electrochemical quartz crystal microbalance with dissipation measurements, or EQCMD, has a venerable history. [3-5] Indeed, one of the incentives for immersing QCMD in liquids in the 1980s was to perform combined EQCMD measurements [6]. The two approaches are complementary in terms of the information they provide about the solid-liquid interface: interfacial mass transfer and structural changes are accessed with QCMD, while electrochemistry is concerned with the interfacial charge transfer and surface potential changes. Of particular interest is the quantitative characterization of electrochemically driven structural or viscoelastic transitions in interfacial layers, e.g., in battery research [7].

To accommodate the needs of researchers working with electrochemical applications in a wide variety of fields, AWSensors developed QCMD instruments with integrated potentiostat/galvanostat control for synchronizing QCMD and electrochemical experiments with appropriate BioLogic potentiostat or galvanostat. To illustrate the functionality, we use a straight-forward aniline polymerization experiment.

Electropolymerization of aniline to form polyaniline (PANI), and its electrochemical properties, have been widely studied, including by electrochemical quartz crystal microbalance (ref. [8-10], and references therein). Here, we go through the necessary steps for setting up an electrochemical experiment with the integrated QCMD/potentiostat combination for following aniline electropolymerization on the gold electrode surface of a QCMD sensor. The gravimetric and electrochemical results are presented, and the gravimetric results are compared with the cyclic voltammetry.

Continue reading by downloading the full Note (below) …

Download Full 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 Technology Notes.

Other references about the Note


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.