Use of torsional resonators to monitor electroactive biofilms
| Autor: | Uwe Schröder, Christopher Moß, Phillipp Sievers, Diethelm Johannsmann |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Biomedical Engineering Biophysics Biosensing Techniques 02 engineering and technology 010402 general chemistry Electrochemistry 01 natural sciences Viscoelasticity Resonator Thin film Softening biology Viscosity business.industry Biofilm Acoustics Equipment Design General Medicine Quartz crystal microbalance 021001 nanoscience & nanotechnology biology.organism_classification Elasticity 0104 chemical sciences Biofilms Quartz Crystal Microbalance Techniques Optoelectronics Geobacter 0210 nano-technology business Biotechnology |
| Zdroj: | Biosensors and Bioelectronics. 110:225-232 |
| ISSN: | 0956-5663 |
| DOI: | 10.1016/j.bios.2018.03.046 |
| Popis: | Whereas the study of interfaces and thin films with the quartz crystal microbalance (QCM) is well established, biofilms have proven to be a difficult subject for the QCM. The main problem is that the shear wave emanating from the resonator surface does not usually reach to the top of the sample. This problem can be solved with torsional resonators. These have a resonance frequency in the range of tens of kHz, which is much below the frequency of the thickness-shear QCMs. The depth of penetration of the shear wave is correspondingly larger. Data acquisition and data analysis can proceed in analogy to the conventional thickness-shear QCM. Torsional resonators may also be operated as electrochemical QCMs (EQCMs), meaning that a DC electrical potential may be applied to the active electrode and that shifts of frequency and bandwidth may be acquired in parallel to the electrical current. Here we report on the formation of mixed-culture biofilms dominated by the microorganism Geobacter anodireducens. The viscoelastic analysis evidences an increase in rigidity as the films grows. Potential sweeps on electroactive biofilms reveal a softening under negative potentials, that is, under conditions, where the layer's metabolism was slowed down by insufficient oxidative activity of the substrate. For comparison, biofilms were monitored in parallel with a conventional thickness-shear QCM. |
| Databáze: | OpenAIRE |
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