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A lab-on-a-chip traveling wave magnetophoresisapproach for sensitiveand rapid protein detection is reported. In this method, a chip-basedmagnetic microarray comprising lines of micrometer-sized thin filmmagnetic elements was used to control the movement of magnetic beads(MBs). The MBs and the chip were functionalized, forming a sandwich-typeassay. The MBs were transported across a detection area, and the presenceof target molecules resulted in the immobilization of MBs within thisarea. Target quantification was accomplished by MB counting in thedetection area using an optical microscope. In order to demonstratethe versatility of the microarray, biotinylated antiavidin was selectedas the target protein. In this case, avidin-functionalized MBs andan avidin-functionalized detection area were used. With a total assaytime of 1 to 1.5 h (depending on the labeling approach used), a limitof detection in the attomole range was achieved. Compared to on-chipsurface plasmon resonance biodetection systems, our method has a largerdynamic range and is about a factor of 500 times more sensitive. Furthermore,our MB transportation system can operate in any chip-based biosensorplatform, thereby significantly improving traditional biosensors. [ABSTRACT FROM AUTHOR]

A travelling surface acoustic wave (TSAW) biosensor on a LiNbO3 piezoelectric substrate is designed and fabricated to study the proliferation of HT-29 and SW-48 cancer cells. The device integrates double interdigital transducers (IDTs) in which the travelling SAW (TSAW) is operating at around 10.3-MHz-centered medical band. The experiments were carried out using label free method, with and without the presence of cell media culture, primary (HT-29) and progressive (SW-48) colon cancer cells. It was noted that at the presence of cancer cells, the sensor response was considerably altered, mostly due to the electroacoustic effect. However, presence of the culture media solution did not have a considerable impact on the frequency response of the biosensors in respect to cells attachment situation. The resonance peaks at the presence of HT-29 cells had fewer shifts toward lower frequencies, compared to SW-48 cells, because of the lower amount of negative electrical charges acquired over the membrane of HT-29 cells. Finite-element analysis (FEA) using COMSOL Multiphysics ® software package is carried out. The numerical results are in good agreement with the experimental ones. It is suggested that using the proposed biosensor is a promising path to detect the proliferation of cancer cells. [ABSTRACT FROM AUTHOR]

Pulsed magnetic fields are generally within the range of frequencies 30-300Hz that are also called Extra Low Frequency (ELF) waves. They are relatively very low energy transmission that bear no side effects to the body. It is reported that they promote blood circulation and tissue regeneration. In this work, rectangular coil connected biomedical PEMF device has been developed. The magnetic field formulation and simulations have been carried out and verified with related sources in the literature. Compared to the analytical results, our results have yielded less than 0.5% error in theoretical derivations and less than 13,1% in experimental measurements. The work is being carried out to obtain portable prototypes for clinical experiments as well. [ABSTRACT FROM AUTHOR]

Piezoelectric sensors are acoustic sensors that enable the selective and label-free detection of biological events in real time. These sensors generate acoustic waves and utilize measurements of the variation of the wave propagation properties as a signal for probing events at the sensor surface. Quartz crystal microbalance (QCM) devices, the most widespread acoustic resonators, allow the study of viscoelastic properties of matter, the adsorption of molecules, or the motility of living cells. In a tutorial-like approach, this review addresses the physical principles associated with the QCM, as well as the origin and effects of major interfering phenomena. Special attention is paid to the possibilities offered by QCM that go beyond microweighing, and important recent examples are presented. [Copyright &y& Elsevier]