Surface functionalization of SPR chip for specific molecular interaction analysis under flow condition

Abstract

Surface functionalization of sensor chip for probe immobilization is crucial for the biosensing applications of surface plasmon resonance (SPR) sensors. In this paper, we report a method circulating the dopamine aqueous solution to coat polydopamine¯lm on sensing surface for surface functionalization of SPR chip. The polydopamine¯lm with available thickness can be easily prepared by controlling the circulation time and the biorecognition elements can be immobilized on the polydopamine¯lm for speci¯c molecular interaction analysis. These operations are all performed under°ow condition in the°uidic system, and have the advantages of easy implementation, less time consuming, and low cost, because the reagents and devices used in the operations are routinely applied in most laboratories. In this study, the speci¯c absorption between the protein A probe immobilized on the sensing surface and human immunoglobulin G in the bu®er is monitored based on this surface functionalization strategy to demonstrated its feasibility for SPR biosensing applications.