Signal Amplification of Surface Plasmon Resonance based on Gold Nanoparticle-Antibody Conjugate and its Application to Protein Array
W. Lee, D-B Lee, Y-W Kim and J-W Choi
Sogang University, KR
surface plasmon resonance, gold nanoparticle
Nanoparticles have offered many diverse capabilities in bioanalysis and biotechnological applications, due to the intrinsic properties of nanoparticle that is distinguished from bulk materials. The integration of nanoparticle, which exhibit unique electronic, photonic, and catalytic properties with biomaterial, which display unique recognition, catalytic, and inhibition property yields novel hybrid nanobiomaterial with synergic properties and functions. In this study, gold (Au) nanoparticle-antibody conjugate was applied for the signal enhancement of surface plasmon resonance (SPR). When small molecule is a target for immobilization or detection, the changes in the angle-dependent attenuated total reflectance (ATR) are often small so the use of SPR method is limited for generic application. The specific interaction between target molecules and Au nanoparticleantibody conjugate induce the change of the surface properties such as mass and roughness, which can be represented as the change of plasmon resonance angle. Antibody was immobilized with an oriented configuration on Au surface. The thickness was measured using ellipsometry (MultiskopTM, Optrel, Germany). Au nanoparticle-antibody conjugated was prepared after coagulation test. The particle size distribution was investigated by electrophoretic light scattering spectrophotometry (ELS-8000, Otuska, Japan). The prepared surface characterization was implemented by atomic force microscopy (AFM, Autoprobe CP, PSI Inc., USA). Experimental results showed that tremendous signal amplification was observed, which represent remarkable advances of SPR technique for ultrasensitive detection. And the detection limit of binding events was also improved.
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Nanotech 2005 Conference Program Abstract