TiN-contained polymer-metal core-shell structured nanocone array: Engineering of sensor performance by controlling plasmonic properties

SENSORS AND ACTUATORS B-CHEMICAL

卷:299

Article

Kawasaki, Daiki¹  Maeno, Kenichi¹  Yamada, Hirotaka¹  Sueyoshi, Kenji¹  Hisamoto, Hideaki¹  Endo, Tatsuro^1,2 

[1] Osaka Prefecture Univ, Grad Sch Engn, Dept Appl Chem, Sakai, Osaka 5998531, Japan

[2] Japan Sci & Technol Agcy, JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 3320012, Japan

关键词: Localized surface plasmon resonance (LSPR);    Biosensor;    Titanium nitride;    Core-shell nanostructure;    Carrier engineering;    DNA detection;   

DOI  :  10.1016/j.snb.2019.126932

来源: Elsevier

【 摘 要 】

Metal nanostructures have great potential for optical label-free biosensors based on localized surface plasmon resonance (LSPR). The sensitivity of a metal nanostructure-based label-free biosensor (i.e., plasmonic sensor) depends on its plasmonic properties, which suffer a decrease in sensitivity by energy losses in the metal material. Here, we demonstrate an approach to improve the plasmonic properties of metal nanostructures by controlling the carrier density in the base polymer material using titanium nitride (TiN). It is expected that the light energy absorbed by TiN is converted into excitons, and it will assist LSPs in the metal nanostructure; thus, the losses of the metal material are compensated by the excitons excited in TiN. We designed a TiN-contained polymer-metal/core-shell structured nanocone array (NCA), comprising TiN nanoparticles (NPs) in a polymer core and metal shell (Au or Ag), and realized improvement of the refractive index (RI) sensitivity of a label-free biosensor by optimizing the TiN-contained polymer composition. As a result, the TiN-contained polymer-metal NCA, with a TiN NP concentration of 10 wt% in the polymer core, had a 1.5-fold higher RI sensitivity than that of the same NCA without TiN NPs. The results of the resistance measurement of the metal surface with the TiN NP-contained polymer (10 wt%) under light exposure suggest the conversion of exposed light into LSPs of metal via TiN. It is suggested that plasmonic properties and sensor performances can be improved by the presented approach. Moreover, in DNA hybridization detection, an extremely low limit of detection of 117.5 fM was achieved.

【 授权许可】

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