| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuM |
| Session: | Biomaterial & Wet Interface Characterization |
| Presenter: | Annika Jokinen, BioNavis, Finland |
| Authors: | E. Jokinen, BioNavis, Finland N.M. Grangvist, BioNavis, Finland W.M. Albers, BioNavis, Finland J.W. Sadowski, BioNavis, Finland |
| Correspondent: | Click to Email |
INTRODUCTION
Surface Plasmon Resonance (SPR) has been used already for a few decades for label-free detection and characterization of biochemical kinetics and affinities of many different types of analytes. The physical phenomenon is not limited to biochemistry, but is applicable to other nanoscale characterization of thin films1.
EXPERIMENTAL METHODS
Aside of the traditional interactions, Multi Parametric Surface Plasmon Resonance (MP-SPR) can be utilized to determine unique refractive index (RI) and thickness (d) of ultrathin (d 0.5-100 nm) and slightly thicker films (d 300 nm- few µm) without prior assumptions of the RI of the material. These are important properties not only for thin film coating industries and applications, but also for gaining important knowledge in biomaterials. Two methods utilizing MP-SPR to thickness and RI calculations have been introduced, either measuring in two different media (2M) with high RI difference, such as air and water1-3 , or at two or more different wavelengths (2W) of light2,3 in order to characterize properties of the thin films.
RESULTS AND DISCUSSION
MP-SPR is suitable for film deposition in situ or ex situ, which makes it compatible with several deposition methods and thereby makes it applicable to a wide range of surfaces also. Polyelectrolyte multilayer deposition in situ was monitored in real-time with MP-SPR. Thickness of each deposited layers was determined utilizing two wavelength method.
Similarly layer thickness and RI was determined also for ex situ spin coated cellulose layer. MP-SPR was used not only to determine thickness and RI of the deposited layer but also for real time monitoring of other molecules interaction to the cellulose model surface4,5.
Recently, MP-SPR was used also to monitor polymer layer structural changes in real time, such as polymer swelling due to pH or electric potential change6. At pH 9 poly (acrylic acid) (PAA) brushes were extended but the brushes collapsed at acidic pH6.
CONCLUSION
With the ability to characterize both kinetics and nanoscale layer properties, MP-SPR proves to be a versatile tool for nanomaterial, biomaterial and biochemical interactions research, which makes MP-SPR invaluable for multidisciplinary research, where both physical and interaction properties of the materials need to be characterized.
REFERENCES
1. Albers, Vikholm-Lundin, Chapter4 in Nano-Bio-Sensing, Springer 2010
2. Liang, et al., Sens.Act.B, 149 (1), 2010
3. Granqvist et al., Langmuir 29 (27), 2013
4. Orelma et al., 12 (12), 2011
5. Kontturi et al., J.Mater. Chem. A, 2013, (ASAP) DOI: 10.1039/C3TA12998E
6. Malmström et al., Macromolecules, 46 (12), 2013