title: Label-free optical detection of aptamer-protein interactions using gold-capped oxide nanostructures.
abstract: Optical biosensors based on noble nanostructures currently receive attention due to their highly efficient, simultaneous analysis of a number of important biomolecules from proteomics to genomics. In this study, the combination of localized surface plasmon resonance (LSPR) with interferometry in the relative reflected intensity (RRI) spectrum of the gold-capped oxide nanostructure was thoroughly exploited for label-free detection of aptamer-protein interactions. The fabrication of gold-capped oxide nanostructure involved the deposition of gold on the surface of porous anodic alumina (PAA) layer chip. This novel nanomaterial enabled us to simultaneously monitor the changes in both LSPR and interferometric characteristics since the biomolecular interactions occur. After immobilizing the aptamer I on the chip surface, our sensor could be easily applied for specific detection of thrombin and aptamer II with a limit of detection of 1 nM thrombin in the sample. Our optical biosensing device connecting with the gold-capped oxide nanostructure has a high potential for highly sensitive monitoring of the other biomolecular interactions such as protein-protein interactions, DNA-protein interactions, DNA-DNA hybridizations, and ligand-receptor interactions with a massively parallel detection capability in a high-throughput system.
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Do-Kyun
authors.initials: DK
authors.lastname: Kim
authors.forename: Kagan
authors.initials: K
authors.lastname: Kerman
authors.forename: Ha Minh
authors.initials: HM
authors.lastname: Hiep
authors.forename: Masato
authors.initials: M
authors.lastname: Saito
authors.forename: Shohei
authors.initials: S
authors.lastname: Yamamura
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Takamura
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Kwon
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D006046:Gold / Q000737:chemistry*; D007368:Interferometry; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D055095:Optics and Photonics; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D020349:Surface Plasmon Resonance
chemical_list: D052157:Aptamers, Nucleotide; D011506:Proteins; D006046:Gold