Optical Sensing with Simultaneous Electrochemical Control in Metal Nanowire Arrays

Sensors

Robert MacKenzie²  Corrado Fraschina²  Takumi Sannomiya²  Vaida Auzelyte¹ 

[1] Laboratory for Micro-/Nano-technology, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland;Laboratory of Biosensors and Bioelectronics, ETH Zurich, Gloriastrasse 35, 8092 Zurich, Switzerland

关键词: nanowire;    sensing;    nanoparticle;    array;    LSPR;    electrochemistry;    nanotechnology;    biosensors;    bioelectronics;   

DOI  :  10.3390/s101109808

来源: mdpi

【 摘 要 】

This work explores the alternative use of noble metal nanowire systems in large-scale array configurations to exploit both the nanowires’ conductive nature and localized surface plasmon resonance (LSPR). The first known nanowire-based system has been constructed, with which optical signals are influenced by the simultaneous application of electrochemical potentials. Optical characterization of nanowire arrays was performed by measuring the bulk refractive index sensitivity and the limit of detection. The formation of an electrical double layer was controlled in NaCl solutions to study the effect of local refractive index changes on the spectral response. Resonance peak shifts of over 4 nm, a bulk refractive index sensitivity up to 115 nm/RIU and a limit of detection as low as 4.5 × 10⁻⁴ RIU were obtained for gold nanowire arrays. Simulations with the Multiple Multipole Program (MMP) confirm such bulk refractive index sensitivities. Initial experiments demonstrated successful optical biosensing using a novel form of particle-based nanowire arrays. In addition, the formation of an ionic layer (Stern-layer) upon applying an electrochemical potential was also monitored by the shift of the plasmon resonance.

【 授权许可】

CC BY   
© 2010 by the authors; licensee MDPI, Basel, Switzerland.