title: Broadband 120 MHz Impedance Quartz Crystal Microbalance (QCM) with Calibrated Resistance and Quantitative Dissipation for Biosensing Measurements at Higher Harmonic Frequencies.
abstract: We developed an impedance quartz crystal microbalance (QCM) approach with the ability to simultaneously record mass changes and calibrated energy dissipation with high sensitivity using an impedance analyzer. This impedance QCM measures frequency shifts and resistance changes of sensing quartz crystals very stable, accurately, and calibrated, thus yielding quantitative information on mass changes and dissipation. Resistance changes below 0.3 Ω were measured with corresponding dissipation values of 0.01 µU (micro dissipation units). The broadband impedance capabilities allow measurements between 20 Hz and 120 MHz including higher harmonic modes of up to 11th order for a 10 MHz fundamental resonance frequency quartz crystal. We demonstrate the adsorbed mass, calibrated resistance, and quantitative dissipation measurements on two biological systems including the high affinity based avidin-biotin interaction and nano-assemblies of polyelectrolyte layers. The binding affinity of a protein-antibody interaction was determined. The impedance QCM is a versatile and simple method for accurate and calibrated resistance and dissipation measurements with broadband measurement capabilities for higher harmonics measurements.
authors.affiliation: Keysight Technologies Austria GmbH, Keysight Labs Linz, Gruberstrasse 40, 4020 Linz, Austria. manuel.kasper@keysight.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Kasper
authors.affiliation: Johannes Kepler University Linz, Biophysics Institute, Gruberstrasse 40, 4020 Linz, Austria. Lukas.Traxler@jku.at.
authors.forename: Lukas
authors.initials: L
authors.lastname: Traxler
authors.affiliation: Faculty of Science, Department of Chemistry, Division of Physical Chemistry University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia. jsalopek@chem.pmf.hr.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Salopek
authors.affiliation: Johannes Kepler University Linz, Biophysics Institute, Gruberstrasse 40, 4020 Linz, Austria. herwigreinhard.grabmayr@students.fh-wels.at.|University of Applied Sciences Upper Austria, School of Engineering, Stelzhamerstrasse 23, 4600 Wels, Austria. herwigreinhard.grabmayr@students.fh-wels.at.
authors.forename: Herwig
authors.initials: H
authors.lastname: Grabmayr
authors.affiliation: Johannes Kepler University Linz, Biophysics Institute, Gruberstrasse 40, 4020 Linz, Austria. Andreas.Ebner@jku.at.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ebner
authors.affiliation: Keysight Technologies Austria GmbH, Keysight Labs Linz, Gruberstrasse 40, 4020 Linz, Austria. ferry_kienberger@keysight.com.
authors.forename: Ferry
authors.initials: F
authors.lastname: Kienberger
mesh_terms: D015374:Biosensing Techniques; D002138:Calibration; D017097:Electric Impedance; D004573:Electrolytes / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques
chemical_list: D004573:Electrolytes
keywords: biosensing; dissipation; higher harmonics; impedance analysis; quartz crystal microbalance