Posts

Antibodies

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.

Biosensor

 

References

[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  

X4-instrument

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 Full Technology Note

You can download the full 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

June 3rd 2020: AWSensors is pleased to announce the release of its new Technology Note on Quartz Crystal Microbalance with Dissipation entitled “AWSensors QCMD“.

Summary of the Note

Advanced Wave Sensors is a company that designs, develops, and manufactures ultra-sensitive sensing systems based on the quartz crystal microbalance with dissipation (QCMD) measurement technology. In this Note the technology basics are explained.

QCM-technology

Introduction

At the core of the QCMD technology is a piezoelectric resonator, typically made of quartz, that is excited to oscillate at its resonance frequency in the thickness-shear mode by applying an alternating current through the electrodes deposited on its surface.

With the resonator oscillating in the thickness shear mode, its two surfaces move in the opposite directions, as indicated by the arrows in Figure 2. The wavelength of the shear wave, λ, is therefore twice the thickness of the sensor, ? = 2? . Because ?? = ? , where ? = √(??/??) , is the speed of shear sound in the material and ? is the frequency, the resonance frequency of such a resonator is given by ?? = ??/2? = (?/2?) √(??/??), where ?? is the shear modulus of quartz, ?? is its density, and ? is the (odd) overtone order. The same expression may be derived formally by solving the equations describing the propagation of shear waves in elastic media subject to appropriate boundary conditions, as discussed in ref. 1. Plugging in 29×109 Pa for the shear modulus of AT quartz and 2650 kg/m3 for the density, one obtains a frequency of ~ 5 MHz for a thickness of ~ 330 um at the fundamental, where n = 1.

Continue reading downloading the full Technology Note (below) …


Download Full Technology Note

You can download the full Technology Note in pdf file from this link or download it from our Technology Web Page where you can find this and the rest of our Technology Notes.