Lithography‐Free Fabrication of Silica Nanocylinders with Suspended Gold Nanorings for LSPR‐Based Sensing. Issue 48 (6th October 2016)

• Record Type: Journal Article
• Authors: Thilsted, Anil Haraksingh; Pan, Jesper Yue; Wu, Kaiyu; Zór, Kinga; Rindzevicius, Tomas; Schmidt, Michael Stenbæk; Boisen, Anja
• Is Part Of: Small. Volume 12:Issue 48(2016)
• Page Start: 6745
• Page End: 6752
• Publication Date: 2016-10-06
• Subjects: fused silica -- LSPR -- nanocylinders -- plasmon -- reactive ion etching; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201602299
• Languages: English
• ISSNs: 1613-6810

Abstract

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 –1 with 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. Abstract : A dense array of fused silica nanocylinders is achieved using lithography‐free reactive ion etching. Varying the etching parameters allows for control of the height and diameter of the nanocylinders. A subsequent gold deposition results in suspended gold nanorings at the tops of the nanocylinders that exhibit localized surface plasmon resonance that can be used for biosensing.