A highly sensitive new label-free bio-sensing platform using radio wave signal analysis, assisted by magnetic beads

We introduce a new label and mediator-free detecting technique for biomaterial based on high frequency signal analysis, assisted by magnetic beads under a no reacting condition of enzyme or chemical. We chose OMSD as the first target material of our device. OMSD is a standard material for identifying the potential of biosensors. It is a chemically treated albumin complex. Thereby using OMSD, we can judge the sensitivity and possibility of the biosensor, not only its monomer target but also its oligomer or polymer target, due to the complex form of OMSD. Furthermore, albumin is a fundamental protein consisting of cell and most abundant protein. Thus, we can even identify the property of protein under a high frequency AC condition. The mechanism of detection is based on the sensitive reflective index change and dielectric constant dispersion in high frequency. It is widely known that the dielectric constant of liquid biopsy is dispersed inherently, depending on the reacting characteristics of solute and solvent under the AC voltage at different frequency ranges. In addition, well arranged beads that are coated with OMSD between the open signal electrodes, affect the reflection and transmission property of the device. The equivalent circuit is also established for obtaining the passive electrical property of OMSD. The components of equivalent circuits consist of the resistance (R), inductance (L), conductance (G), and capacitance (C). Additionally, the decomposing technique also provides Residual Signal (RS), and propagation constant (γ) from measured power signals. These various parameters, which are obtained by the analytical signal processing, exhibit more reliable results for instant in-situ sensing without any added supporters for reaction. Moreover, our device has some advantages of being reusable, having ream time sensing, and a high applicability.