title: A highly sensitive and label free biosensing platform for wireless sensor node system.
abstract: 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.
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, Seoul, South Korea.
authors.forename: Sang-Gyu
authors.initials: SG
authors.lastname: Kim
authors.forename: Hee-Jo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Hyo-Il
authors.initials: HI
authors.lastname: Jung
authors.forename: Jong-Gwan
authors.initials: JG
authors.lastname: Yook
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D018076:DNA, Complementary / Q000032:analysis*; D004867:Equipment Design; D057230:Limit of Detection; D011846:Radio Waves; D013016:Sound; D019809:Streptavidin / Q000032:analysis*
chemical_list: D018076:DNA, Complementary; D019809:Streptavidin
keywords: Biomolecule; Biosensor; Radio-frequency; Surface acoustic wave filter; Wireless sensor node