Capabilities of Piezoelectric Immunosensors for Detecting Infections and for Early Clinical Diagnostics

Use of Piezoelectric Immunosensors for Detection of Interferon-Gamma Interaction with Specific Antibodies in the Presence of Released-Active Forms of Antibodies to Interferon-Gamma

“…Analysis of liquids with the use of piezoelectric sensors can be carried out both in a static and a flowing mode. In the first case (the procedure being known as “dip and dry”), increase of the receptor layer mass is measured before and after contact of the sensor with the analyzed liquid sample and further air-drying to constant mass, whereas in the second case (flowing mode) signal from the sensor is measured continuously [ 19 ]. The test samples were analyzed in the flowing mode.…”

“…, adhesion of particles with Ag or Abs bound to their surfaces [ 7 , 8 ]; (3) detection relying on the use of various labels [ 9 , 10 , 11 , 12 , 13 , 14 ]; (4) detection techniques employing rapid, portable, high-sensitivity sensors. The latter include immunochromatographic systems [ 15 , 16 ], immunochips [ 17 ], or immunosensors [ 14 , 18 ], which represent a fast-developing approach in laboratory analysis using various types of biologically sensitive elements to furnish information about the Ag-Abs interaction in the form of electrical signals [ 19 ]. The important distinction of immunosensor assays is the method of signal transduction which may employ either an electrochemical or an optical transducer [ 20 ].…”

“…In the case of optical transducers, Ag-Abs quantification is based on the generation of light signals (color change or fluorescence) or changes in the optical properties of the environment [ 23 ]. Among major advantages of immunosensors are the rapidity of analysis, convenience of use, possibility of quantification with subsequent mathematical processing, portability of the test devices and high sensitivity [ 19 ].…”

“…This type of immunosensor is characterized by fast response and ease of operation, integrability into multisensory systems or automatic data acquisition systems [ 25 ]. The unparalleled feature of PI is that they compromise high sensitivity ensured by the use of QCR as a transducer element and selectivity, which is determined by the specificity of receptor molecules employed [ 19 ]. The principle behind PI operation is the detection of frequency variations of the electrical signal following Ag-Abs complex formation, resulting in an increase of mass sensed by the quartz plate of the resonator or cantilever.…”

Bulk and Surface Acoustic Wave Biosensors for Milk Analysis

“…Providing a sufficient size of the analyte, the signal response can be enhanced by another capture molecule binding to the analyte captured on the surface, which leads to the so-called sandwich assay test format ( Figure 3 b). Labeling the other capture molecule, e.g., using nanoparticles, may further enhance the signal response [ 15 , 58 ].…”