Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7138750 | Sensors and Actuators B: Chemical | 2018 | 7 Pages |
Abstract
Surface-plasmon resonance (SPR) sensors represent a formidable technology for molecular biology and bioanalytics applications. Here, we devise a new interrogation architecture that transforms a standard SPR chip into an optical-heterodyne clock detector comparable with the best SPR instruments. The key ingredients are (i) the conversion of refractive-index changes on the SPR chip into frequency shifts of an oscillatory electronic signal (ii) a differential probe & reference optical-cavity scheme that cancels out most source/detector noise contributions. A rigorous characterization of the sensor performance with the integration time demonstrates a refractive-index resolution on the 10â8-RIU level over a 1-s timescale using a bare, unstabilized SPR element. A bio-sensing test with a functionalized surface interfaced with a microfluidic flow-cell is carried out, showing detection of streptavidin via covalent bond down to concentrations of 90â¯fg/mm2.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
A. Giorgini, S. Avino, P. Malara, R. Zullo, P. De Natale, K. Mrkvová, J. Homola, G. Gagliardi,