A single light spot GC detector employing localized surface plasmon resonance of porous Au@SiO2 nanoparticle multilayer

• Published in: Analyst (London) 2019-01, Vol.144 (2), p.698-706
• Main Authors: Lin, Pei-Ying, Le, Guarn-Yi, Chiu, Wei-I, Jian, Rih-Sheng, Lu, Chia-Jung
• Format: Article
• Language: English
• Subjects: Cyclohexanone; Gas chromatography; Glass; Gold; Multilayers; Nanoparticles; Permeability; Response time; Sensors; Silicon dioxide; Surface plasmon resonance; Xylene
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c8an01921e

This paper describes the synthesis of a nano-porous multilayered film consisting of Au@SiO2 nanoparticles. This film was used to miniaturize the size of a localized surface plasmon resonance (LSPR)-based capillary gas chromatograph (GC) detector. A layer-by-layer (LbL) approach with proper surface reaction sequences was used to create a multilayer structure that consisted of as many as five layers of Au@SiO2 nanoparticles. The center wavelength of LSPR was shifted from 520 to 634 nm due to the approximation of additional layers of nanoparticles. The vapor response time for this Au@SiO2 multilayer LSPR sensor was identical to that of an Au nanoparticle monolayer, which confirmed that this multilayer structure has a high level of gas permeability. The multilayer was synthesized inside a glass capillary for use as a GC detector. Due to the enhancement of absorbance, the gas chromatographic signal was obtained via a single spotlight that penetrated one side of the glass capillary and was then reflected by a silver mirror coated on the opposite side. The detection limits were ≤20 ng for cyclohexanone and m-xylene.