title: High sensitivity molecule detection by plasmonic nanoantennas with selective binding at electromagnetic hotspots.
abstract: We report a highly sensitive biomolecule detection by plasmonic nanoantenna arrays with selective binding at the optical hotspots. The plasmonic nanoantennas consist of two separated Au nanorods with a thin Ti disk placed in between. By using selective surface modification chemistry, controlled binding occurs only in the gaps between the plasmonic nanoantennas, which ensures a high detection sensitivity. Both optical characterization using a dark field microscope and the FDTD simulation show that after the streptavidin binding, the signal increases with decreasing gap size. Compared to a single nanorod, the signal obtained per bound molecule in the nanoantennas increases by a factor of six, which is promising with respect to the future detection of single molecules.
authors: Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore 117602. jh-teng@imre.a-star.edu.sg.
authors: Nan
authors: N
authors: Zhang
authors: Yan Jun
authors: YJ
authors: Liu
authors: Jing
authors: J
authors: Yang
authors: Xiaodi
authors: X
authors: Su
authors: Jie
authors: J
authors: Deng
authors: Chan Choy
authors: CC
authors: Chum
authors: Minghui
authors: M
authors: Hong
authors: Jinghua
authors: J
authors: Teng
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001710:Biotin / Q000737:chemistry; D002412:Cations; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry; D008853:Microscopy / Q000379:methods; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D043942:Nanotubes / Q000737:chemistry; D055095:Optics and Photonics; D010100:Oxygen / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D015203:Reproducibility of Results; D019809:Streptavidin / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D002412:Cations; D011092:Polyethylene Glycols; D001710:Biotin; D006046:Gold; D019809:Streptavidin; D014025:Titanium; D010100:Oxygen