Superhydrophobic-Oleophobic Ag Nanowire Platform: An Analyte-Concentrating and Quantitative Aqueous and Organic Toxin Surface-Enhanced Raman Scattering Sensor

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• 作者：Xing Li ; Hiang Kwee Lee ; In Yee Phang ; Choon Keong Lee ; Xing Yi Ling
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：October 21, 2014
• 年：2014
• 卷：86
• 期：20
• 页码：10437-10444
• 全文大小：456K
• ISSN：1520-6882

文摘

The ultratrace detection and quantification of toxins in both water and organic liquids remains a challenge due to the random spreading and dilution of liquids on substrate-based sensors, especially for organic liquids with low surface tension. Herein, we fabricate a superhydrophobic-oleophobic (SHP-OP) 3D Ag nanowire mesh-like surface-enhanced Raman scattering (SERS) platform to overcome the random spreading issue, demonstrating ultratrace toxin sensing in both water and organic liquid. Our SHP-OP SERS platform is able to concentrate analyte solutions in water and toluene to 100-fold and 8-fold smaller areas, respectively, as compared to its omniphilic counterparts. The synergy of analyte-concentrating ability and intense SERS-enhancing properties on our SHP-OP SERS platform enables quantitative and ultratrace detection of melamine and Sudan I down to 0.1 fmol in water and toluene, respectively, using just 1 渭L of analyte solution. These detection limits are 10³-fold lower than the regulatory limits, clearly indicating our SHP-OP SERS platform as an appealing universal ultratrace toxin sensor. The ultratrace detection of spiked melamine in liquid milk down to 100 fmol also highlights the suitability of our SHP-OP SERS platform for the sensing of food toxins in real samples.