In this paper, we propose a radio-frequency (RF) biosensor platform based on oscillation frequency deviation at 2.4. GHz. Its feasibility is experimentally demonstrated with the well-known biomolecular binding systems such as biotin-streptavidin and deoxyribonucleic acid (DNA) hybridization. For a basic principle of our biosensing system, the impedance of a resonator with the biomolecular immobilization is at first varied so that the corresponding change results in frequency change of an oscillator. Especially, to enhance the sensitivity of the proposed system, a surface acoustic wave (SAW) filter having a high-Q factor (~2000) is utilized. From the resulting component, even a small change of oscillation frequency can be transformed into a large output amplitude variation. According to the experimental results, it is found that our system shows the low detectable limit (~1. ng/ml) and fast response time (~real-time) for different target biomolecules, i.e. streptavidin and complementary DNA (cDNA). As a result, we find that our device is an effective biosensing system that can be used for a label-free and real-time measurement of the biomolecular binding events.
Bibliographical noteFunding Information:
This research has been supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2013R1A1A2A10009871) and the Yonsei University Research Fund of 2013.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering