Nanocharacterization of soft biological samples in shear mode with quartz tuning fork probes

• Published in: Sensors (Basel, Switzerland) Vol. 12; no. 4; pp. 4803 - 4819
• Main Authors: Otero, Jorge, Gonzalez, Laura, Puig-Vidal, Manel
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.04.2012; MDPI Publishing; Molecular Diversity Preservation International (MDPI)
• Subjects: Amplitude modulation; Atomic force microscopy; Bacteria; Bacteris; Bioengineering; Bioenginyeria; Biological; Biology; Biomolecules; Biomolècules; Citologia; Cytology; Experiments; Frequency modulation; Lasers; Microscopy; Microscòpia de força atòmica; nanocharacterization; Nanocomposites; Nanomaterials; Nanostructure; Nanotechnology; Nanotecnologia; Sensors; Topography; Tuning; tuning fork; atomic force microscopy; tuning fork; nanocharacterization
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s120404803

Quartz tuning forks are extremely good resonators and their use is growing in scanning probe microscopy. Nevertheless, only a few studies on soft biological samples have been reported using these probes. In this work, we present the methodology to develop and use these nanosensors to properly work with biological samples. The working principles, fabrication and experimental setup are presented. The results in the nanocharacterization of different samples in different ambients are presented by using different working modes: amplitude modulation with and without the use of a Phase-Locked Loop (PLL) and frequency modulation. Pseudomonas aeruginosa bacteria are imaged in nitrogen using amplitude modulation. Microcontact printed antibodies are imaged in buffer using amplitude modulation with a PLL. Finally, metastatic cells are imaged in air using frequency modulation.