Organic isocyanide-adsorbed gold nanostructure: a SERS sensory device for indirect peak-shift detection of volatile organic compounds

• Published in: Analyst (London) Vol. 137; no. 8; pp. 193 - 1936
• Main Authors: Kim, Kwan, Lee, Ji Won, Shin, Dongha, Choi, Jeong-Yong, Shin, Kuan Soo
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 21.04.2012
• Subjects: Analytical chemistry; Carbon tetrachloride; Chemistry; Exact sciences and technology; General, instrumentation; Gold; Nanoparticles; Nanostructure; Numerical control; Organic compounds; Partial pressure; Spectrometric and optical methods; Stretching; Trace analysis; Shift; Gold; Butylamine; Nanoparticle; Device; Use; Volatile organic compound; Nanostructure; Chemical sensor; Chemical enrichment; Partial pressure; Adsorption; Detection limit; Surface Enhanced Raman Spectrometry; Noble metal; Peak; Technique; Detection; Isocyanide; Surface potential
• ISSN: 0003-2654; 1364-5528; 1364-5528
• DOI: 10.1039/c2an16044g

Organic isocyanide adsorbed on a noble metal nanostructure can be used as a platform for a volatile organic compound (VOC) sensor operating via surface-enhanced Raman scattering (SERS). This is possible since the NC stretching band of organic isocyanides such as 2,6-dimethylphenylisocyanide (2,6-DMPI) is very susceptible to the surface potential of Au onto which 2,6-DMPI is assembled. The surface potential of Au nanoparticles is even subject to change by VOCs, which can be easily monitored by the SERS of 2,6-DMPI. Thereby, under the flow of CCl 4 vapor at a partial pressure of 12.8 kPa, for instance, the NC stretching band is blue-shifted by up to 20 cm 1 within 30 s, corresponding to a potential change of +0.56 V. Conversely, under the flow of butylamine at 12.8 kPa, the NC stretching band is red-shifted, instead of being blue-shifted, by as much as 12 cm 1 . At lower partial pressures, even a blue- or red-shift of 1 cm 1 was reproducibly measured at a partial pressure of 125 mPa, corresponding to 6.5 ppm for CCl 4 , suggesting that the present detection limit is superior to the results obtained via other techniques, especially those operating based on gold nanoparticles and aggregates. Schematic representation of the 2,6-dimethylphenylisocyanide (2,6-DMPI) adsorbed poly(ethylenimine) (PEI)-stabilized gold nanostructure which can be used as a platform for a volatile organic chemical sensor operating via Raman scattering spectroscopy.