A label-free biosensing platform using a PLL circuit and biotin-streptavidin binding system

Yunseog Hong, Hee Jo Lee, Sang Gyu Kim, Byung Hyun Kim, Gi Ho Yun, Jong Gwan Yook

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


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 (∼ 61kHz/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.

Original languageEnglish
Article number6919347
Pages (from-to)345-352
Number of pages8
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number3
Publication statusPublished - 2015 Jun 1

All Science Journal Classification (ASJC) codes

  • Biomedical Engineering
  • Electrical and Electronic Engineering


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