Biomedical subjects

M von Schickfus

Publications and source records attributed to M von Schickfus.

3 recordsLinked to original sources

PubMed1999

A contactless surface acoustic wave biosensor.

Surface acoustic wave sensors operating in liquid generally cause problems resulting from wire bonding. The authors present an approach for a biosensor where the need for bonding wires is eliminated by utilizing inductive coupling of the sensor device to the RF circuitry. Protection of the electrodes from the liquid is achieved by coating the device surface with a SiO2 layer, resulting in a simplified handling of the devices. The first measurements with a sensor operating at 420 MHz are presented, demonstrating the potential of this operating principle for biosensing.

Acoustics↗

PubMed1998

Viscoelastic behavior of antibody films on a shear horizontal acoustic surface wave sensor.

To study the viscoelastic behavior of antibody films on a surface acoustic wave device, we have measured the influence of multiple layers of antibodies onto the propagation of the wave. Attenuation and sound velocity variation caused by up to 20 layers have been measured. The results can be interpreted with the propagation of a viscously damped Love wave in a film with an extremely low velocity of sound. From our results, we conclude that, for the one- or two-layer films normally used in acoustic wave immunosensing, a pure mass effect is dominant. For thick films, a saturation of the sensor response is observed.

Animals↗

PubMed1996

Development of a surface acoustic wave immunosensor.

In this paper the first application of horizontal polarized surface acoustic waves (HP-SAW) in LiTaO3 for an immunosensor is presented. A SAW device with two paths, a sensitive path and a reference path operating in liquid at 345 MHz, is used as the sensor. Antigens and antibodies were both immunoglobulins. The antibodies were immobilized via protein A on the sensitive path with a mass density of 0.4 ng/mm2, as shown by ELISA measurements. A theoretical detection limit of approximately 33 pg and a high sensitivity of 110 kHz/(ng/mm2) could be derived from the experiments. High signal enhancement factors of 4.5 and 12 are achievable by gold colloid labeled antigens with colloid diameters of 5 and 10 nm, respectively. Specificity of the antibody was demonstrated by a preabsorption experiment. As a further antibody/antigen system the binding of the anti-human serum albumin (HSA) to HSA was examined.

Antibodies↗