title: Lithography-Free Fabrication of Silica Nanocylinders with Suspended Gold Nanorings for LSPR-Based Sensing.
abstract: Tunable plasmonic platforms are important for a variety of applications such as photovoltaics, LED's, optoelectronics, medical research, and biosensors. In particular, development of label-free plasmonic biosensors is one of the key research areas that utilizes plasmonic nanostructures for detection of biologically relevant molecules at low concentrations. The authors have developed a cost-effective, fast, and lithography-free method to fabricate transparent fused silica nanocylinders. The technique allows tuning of nanocylinder height, diameter, and density and can be scaled to large surface areas, such as 8 in. wafers. The authors demonstrate that gold coated nanocylinders support localized surface plasmon resonances (LSPR) from visible to near infrared wavelengths. The plasmonic platform can be characterized as suspended gold nanorings and exhibits a sensitivity of 658 nm RIU-1with a figure-of-merit of 10, comparable to other state-of-the-art LSPR sensing platforms that utilize more complex nanofabrication pathways. It was observed that the LSPR peak positions can be controlled by varying the geometry of the nanocylinders. The authors illustrate surface functionalization, biosensing, and surface regeneration properties of the platform using thiols and detection of bovine serum albumin (BSA). The observed LSPR shifts for 11-mercaptoundecanoic acid and BSA was 12 and 26 nm, respectively.
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Anil Haraksingh
authors.initials: AH
authors.lastname: Thilsted
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Jesper Yue
authors.initials: JY
authors.lastname: Pan
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Kaiyu
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Kinga
authors.initials: K
authors.lastname: Zór
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Tomas
authors.initials: T
authors.lastname: Rindzevicius
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Michael Stenbaek
authors.initials: MS
authors.lastname: Schmidt
authors.affiliation: Department of Micro- and Nanotechnology, The Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
authors.forename: Anja
authors.initials: A
authors.lastname: Boisen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold; D012822:Silicon Dioxide
keywords: LSPR; fused silica; nanocylinders; plasmon; reactive ion etching