Grating-Coupled Surface-Plasmon-Resonance Biosensor Discs with a C-Type Fluidic Channel for Monitoring Growth of Self-Assembled Monolayer

In this paper, we present a grating-coupled surface plasmon resonance (SPR) biosensor with a c-type fluidic channel on a grating disc. For obtaining the kinetic information of molecular interaction, we combined a c-type fluidic channel on disc to drive testing solution forward by gravity via turning the grating disc. The disc biosensor can react with probe molecules on the different sensing surfaces in the following time. The repeatability testing shows the resolution of angle of the measuring system was enhanced by threefold comparing to that without the automation improvement. In order to identify the accuracy of angle changes of SPR due to the chemical reaction on surface, experiment for monitoring a growth self-assembled monolayer (SAM) immobilized on gold surface was performed. The measured response curves show that the saturation time of the SAM formation, which thickness is smaller than 2 nm, is roughly 5 hours when 1 mM MHDA growing on gold at room temperature. The demonstration reveals that the disc biosensor with c-type fluidic channels can be a promising tool for a kinetic analysis of bimolecular interaction without any external fluid pumping systems.