title: A Label-Free Biosensing Platform Using a PLL Circuit and Biotin-Streptavidin Binding System.
abstract: This paper proposes a novel RF biosensor that utilizes a frequency synthesizer associated with a microstrip open-loop resonator for label-free biomolecular detection. The RF biosensor consists mainly of a resonance-assisted transducer and a phase locked loop (PLL) circuit. In this work, the performance of the RF biosensor is validated using the well-known biotin-streptavidin binding system. When biotin is bound to streptavidin, the input impedance of the resonator is varied, resulting in a change in the oscillation frequency. The concentration of the streptavidin is ultimately detected by a voltage signal of the PLL's loop filter with simple measurement equipment. According to the experimental results, the RF biosensor has revealed excellent sensitivity ( ~ 61 kHz/ngml(-1)) and a low detection limit ( ~ 1 ng/ml), as well as a rapid response. These results demonstrate that the RF biosensor can be an effective sensing platform for label-free detection in a biomolecular binding system.
authors.lastname: Yunseog Hong
authors.lastname: Hee-Jo Lee
authors.lastname: Sang-Gyu Kim
authors.lastname: Byung-Hyun Kim
authors.lastname: Gi-Ho Yun
authors.lastname: Jong-Gwan Yook
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D001710:Biotin / Q000378:metabolism*; D004867:Equipment Design; D057230:Limit of Detection; D019809:Streptavidin / Q000378:metabolism*
chemical_list: D001710:Biotin; D019809:Streptavidin