Composite layer based plasmon waveguide resonance for label-free biosensing with high figure of merit

A plasmon waveguide resonance (PWR) sensing structure was presented based on composite waveguide layer in this article. This composite layer based PWR (CLPWR) could provide stronger evanescent electric field and sharper resonance curve than surface plasmon resonance (SPR). Owing to these, the CLPWR sensor could provide up to 20 times higher resolution than the conventional SPR technology under ideal conditions. The vacuum coating techniques and optimal optical arrangements were developed for the realization of CLPWR sensor, and the residual analysis was introduced to quantify the effect of experimental system noise on measurement accuracy. In the label free biosensing experiment, it was demonstrated that the CLPWR sensor could provide more accurate measurement results than conventional SPR sensor for label free biomolecular interaction analysis in complex media.