Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 Jan 1;100:15-20. doi: 10.1016/j.saa.2012.02.079. Epub 2012 Mar 2.
We demonstrate that the NC stretching band of 2,6-dimethylphenylisocyanide (2,6-DMPI) adsorbed on poly(ethylenimine)-capped Au film is very susceptible to the kind of biogenic volatile organic compounds (VOCs) exposed, suggesting that the isocyanide-adsorbed noble metal nanostructures can be used as a platform for a biogenic VOC sensor operating via surface-enhanced Raman scattering (SERS). Specifically, first we demonstrate that highly SERS-active Au films can easily be fabricated onto the inner surfaces of glass capillaries, being able to measure the SERS spectra of 2,6-DMPI facilely and thus to monitor the shift of its NC stretching band rapidly in response to a variety of biogenic VOCs including isoprene, farnesol, and (+)-α-pinene. Secondly, we are able to deduce from the NC stretching peak shifts that farnesol must act as an electron acceptor so as to increase the surface potential of Au nanoparticles, while isoprene and (+)-α-pinene are electron donors, resulting in the decrease in the surface potential of Au nanoparticles. To our knowledge, this is the first report, informing the applicability of SERS, though indirect, in the detection of biogenic VOCs.
我们证明，吸附在聚（乙二胺）包覆金膜上的 2,6-二甲基苯异氰酸酯（2,6-DMPI）的 NC 伸缩带对暴露的生物挥发性有机化合物（VOC）非常敏感，这表明异氰酸酯吸附的贵金属纳米结构可以用作通过表面增强拉曼散射（SERS）运行的生物 VOC 传感器的平台。具体来说，首先我们证明了高 SERS 活性的 Au 膜可以很容易地制备到玻璃毛细管的内表面上，能够轻松测量 2,6-DMPI 的 SERS 光谱，从而能够快速监测其 NC 伸缩带的位移以响应各种生物 VOC，包括异戊二烯、法呢醇和（+）-α-蒎烯。其次，我们可以从 NC 伸缩峰的位移推断出法呢醇必须作为电子受体，以增加 Au 纳米颗粒的表面电势，而异戊二烯和（+）-α-蒎烯是电子供体，导致 Au 纳米颗粒的表面电势降低。据我们所知，这是第一个通过间接的方式报告 SERS 在检测生物 VOC 中的适用性的报告。
