Real-Time, Label-Free Detection of Biomolecular Interactions in Sandwich Assays by the Oblique-Incidence Reflectivity Difference Technique

Sensors

Yung-Shin Sun¹ 

[1] Department of Physics, Fu-Jen Catholic University, New Taipei City 24205, Taiwan

关键词: label-free biosensor;    oblique-incidence reflectivity difference (OI-RD);    protein-protein interaction;    protein-small molecule interaction;    real-time kinetics;   

DOI  :  10.3390/s141223307

来源: mdpi

【 摘 要 】

One of the most important goals in proteomics is to detect the real-time kinetics of diverse biomolecular interactions. Fluorescence, which requires extrinsic tags, is a commonly and widely used method because of its high convenience and sensitivity. However, in order to maintain the conformational and functional integrality of biomolecules, label-free detection methods are highly under demand. We have developed the oblique-incidence reflectivity difference (OI-RD) technique for label-free, kinetic measurements of protein-biomolecule interactions. Incorporating the total internal refection geometry into the OI-RD technique, we are able to detect as low as 0.1% of a protein monolayer, and this sensitivity is comparable with other label-free techniques such as surface plasmon resonance (SPR). The unique advantage of OI-RD over SPR is no need for dielectric layers. Moreover, using a photodiode array as the detector enables multi-channel detection and also eliminates the over-time signal drift. In this paper, we demonstrate the applicability and feasibility of the OI-RD technique by measuring the kinetics of protein-protein and protein-small molecule interactions in sandwich assays.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.