title: Highly sensitive nano-porous lattice biosensor based on localized surface plasmon resonance and interference.
abstract: We propose a design for a highly sensitive biosensor based on nanostructured anodized aluminum oxide (AAO) substrates. A gold-deposited AAO substrate exhibits both optical interference and localized surface plasmon resonance (LSPR). In our sensor, application of these disparate optical properties overcomes problems of limited sensitivity, selectivity, and dynamic range seen in similar biosensors. We fabricated uniform periodic nanopore lattice AAO templates by two-step anodizing and assessed their suitability for application in biosensors by characterizing the change in optical response on addition of biomolecules to the AAO template. To determine the suitability of such structures for biosensing applications, we immobilized a layer of C-reactive protein (CRP) antibody on a gold coating atop an AAO template. We then applied a CRP antigen (Ag) atop the immobilized antibody (Ab) layer. The shift in reflectance is interpreted as being caused by the change in refractive index with membrane thickness. Our results confirm that our proposed AAO-based biosensor is highly selective toward detection of CRP antigen, and can measure a change in CRP antigen concentration of 1 fg/ml. This method can provide a simple, fast, and sensitive analysis for protein detection in real-time.
authors: School of Electrical Engineering and Computer Science, Kyungpook National University, 1370 Sankyuk-dong, Bukgu, 702-701 Daegu, South Korea.
authors: Se-Hyuk
authors: SH
authors: Yeom
authors: Ok-Geun
authors: OG
authors: Kim
authors: Byoung-Ho
authors: BH
authors: Kang
authors: Kyu-Jin
authors: KJ
authors: Kim
authors: Heng
authors: H
authors: Yuan
authors: Dae-Hyuk
authors: DH
authors: Kwon
authors: Hak-Rin
authors: HR
authors: Kim
authors: Shin-Won
authors: SW
authors: Kang
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D055910:Antibodies, Immobilized; D000941:Antigens / Q000032:analysis / Q000276:immunology; D002097:C-Reactive Protein / Q000032:analysis / Q000276:immunology; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D055910:Antibodies, Immobilized; D000941:Antigens; D008567:Membranes, Artificial; D006046:Gold; D002097:C-Reactive Protein; D000537:Aluminum Oxide