A combined nanoplasmonic and electrodeless quartz crystal microbalance setup.

We have developed an instrument combining localized surface plasmon resonance (LSPR) sensing with electrodeless quartz crystal microbalance with dissipation monitoring (QCM-D). The two techniques can be run simultaneously, on the same sensor surface, and with the same time resolution and sensitivity as for the individual techniques. The electrodeless QCM eliminates the need to fabricate electrodes on the quartz crystal and gives a large flexibility in choosing the surface structure and coating for both QCM-D and LSPR.

Alpha-helical peptide-induced vesicle rupture revealing new insight into the vesicle fusion process as monitored in situ by quartz crystal microbalance-dissipation and reflectometry.

We have used simultaneous quartz crystal microbalance-dissipation (QCM-D) monitoring and four-detector optical reflectometry to monitor in situ the structural transformation of intact vesicles to a lipid bilayer on a gold surface. The structural transformation of lipid vesicles to a bilayer was achieved by introducing a particular amphipathic, alpha-helical (AH) peptide. The combined experimental apparatus allows us to simultaneously follow the acoustic and optical property changes of the vesicle rupturing process upon interaction with AH peptides.

QCM-D and reflectometry instrument: applications to supported lipid structures and their biomolecular interactions.

A novel setup was recently developed, combining quartz crystal microbalance with dissipation monitoring (QCM-D) and optical reflectometry for measurements on one and the same surface of, for example, biomolecular adlayers and interactions ( Rev. Sci. Instr.

A combined reflectometry and quartz crystal microbalance with dissipation setup for surface interaction studies.

We have developed an instrument for surface interaction studies, which combines a newly invented four detector optical reflectometry setup with quartz crystal microbalance with dissipation (QCM-D) monitoring. The design is such that data from both techniques can be obtained simultaneously on the same sensor surface, with the same signal-to-noise ratio and time resolution, as for the individual techniques. In addition, synchronized information about structural transformations, molecular mass, and the hydration of thin films on solid surfaces can be obtained on the same specimen, as validated by monitoring the formation of supported lipid bilayers on a silica-coated QCM sensor surface.

Light-regulated release of liposomes from phospholipid membranes via photoresponsive polymer-DNA conjugates.

A method for releasing tethered liposomes from a supported lipid bilayer in response to a light stimulus is described. The tethering is accomplished through the hybridization of end-functionalized DNA that resides on both the supported lipid bilayer and liposome surfaces. Normally consisting of cholesterol or lipid tails, the end group is replaced in this study by a photoresponsive polymer that partitions into lipid bilayers at physiological pH.

Investigation of binding event perturbations caused by elevated QCM-D oscillation amplitude.

We report measurements with the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, with focus on how the shear oscillation amplitude of the sensor surface influences biorecognition binding events. Technically, this is made as reported recently (M. Edvardsson, M.

A dual-frequency QCM-D setup operating at elevated oscillation amplitudes.

An often raised, but rarely addressed, question with respect to applications of the quartz crystal microbalance technique is whether the shear oscillation of the sensor surface influences the adsorption kinetics or binding events being studied. Motivated by this uncertainty, as well as by the possibility of using elevated amplitudes to influence and steer specific biomolecular interactions, we have further developed the quartz crystal microbalance with dissipation monitoring (QCM-D) technique to operate in dual-frequency mode. One mode (one harmonic) is utilized for continuous excitation of the QCM-D sensor at resonance, at variable driving amplitudes, while the other mode (another harmonic) is used for combined frequency and energy dissipation (damping) measurements.