|AVS 55th International Symposium & Exhibition|
|Biomaterial Interfaces||Thursday Sessions|
|Session:||Plasmonics and Magneto/Plasmonics Aimed at Biosensing|
|Presenter:||P. Lisboa, JRC-European Commission, IHCP, Italy|
|Authors:||P. Lisboa, JRC-European Commission, IHCP, Italy
A. Valsesia, JRC-European Commission, IHCP, Italy
I. Mannelli, JRC-European Commission, IHCP, Italy
P. Colpo, JRC-European Commission, IHCP, Italy
F. Rossi, JRC-European Commission, IHCP, Italy
|Correspondent:||Click to Email|
The implementation of sensor platforms providing high sensitivity of detection is a crucial step for the design of the new analytical device generation for biosensor developments. Designing platform with active/non-actives region at nanoscale has shown already a drastic increase of detection sensitivity.1,2 The use of organothiols to create nanopatterns has been already studied showing that this type of chemistry is indicated to produce chemical contrasts for bio-applications.3 In this work, the effect of organothiols-nanopattern in Surface Plasmon Resonance imaging (SPRi) detection was studied. The gold surface of the SPRi chip was divided in two areas, one modified with a chemical nano-contrast based in two different organothiols (thiolated polyethylene oxide (PEO) and Mercaptohexadecanoic acid (MHD) and the other modified uniformly with MHD. The SPRi study was based on the detection of the immunoreaction between Human IgG and anti-Human IgG (Ab specific) by comparing the results obtained with nanostructured and uniform carboxylic surface. First Human IgG was immobilised on the chip and after the recognition of different concentrations of anti-Human IgG was realised. The achieved SPRi signal was higher in the case of the nanostructured areas for all the tested concentrations. Since the active surface with carboxylic functionalities presented only 3% of the total area, one would expect the detection signal to be 3% of the signal obtained for the uniform MHD surface. The fact that the signal from the nanostructures is higher than in the MHD surfaces in SPRi detection is related to an amplification of signal due to the 2D crystalline character of the structures. This type of arrangement presents the geometry of a photonic crystal leading to the interaction between the Surface plasmon polaritron modes and the regular modulation of the dielectric constant of the surface above the gold film modifying the plasmon effect and consequently increasing the measured reflectivity. These results indicate that SPRi detection performance can be improved by the rational functionalisation of the prism surface with 2D crystalline nanopatterns. Moreover adhesive – nonadhesive nanopatterns are recognized to be good platforms for the correct immobilization of the biomolecules on biosensing surfaces.
1K. Lee, et al., Nano-Letters, 2004 4, 1869.
2A. Valsesia, et al., Langmuir 2006, 22, 1763.
3P. Lisboa, et al., Applied Surface Science, 2006, 253, 4796.