SPDS for Oligonucleotide Hybridization

With the features of field-enhanced, quadratic signal amplification and its self-referencing property [16-18], SPDS has shown improved sensitivity compared to the normal SPR in biosensing applications. Especially, it generates a significantly improved signal-to-noise ratio in the study of oligonucleotide hybridization, where a classical SPR sensor is usually poorly qualified. 

A multi-layer surface architecture composed of SAM/streptavidin/probe was employed for the hybridization study (Fig. 19). Since the streptavidin density on the functional stripes was identical to that on a homogenous surface [9], i.e., 2.2 x 1012 molecules cm-2, the probe density was estimated to be 2.9 x 1012 molecules cm 2 by knowing from the diffraction signal the binding stoichiometry between streptavidin and the probe (ca. 0.75) [16], 

The saturation response of the T15-1 target at 3 pM is estimated to be 1.8 x 1012 molecules cm 2 by comparing the diffraction signal between probe and target and determining their binding stoichiometry. The response from the 5 nM 

This contribution has attempted to summarize a wide variety of work from our group employing SPR, SPFS, and SPDS analysis, specifically for investigations 

---