se6b00749_si_003.avi (1.72 MB)

Hand-Held Femtogram Detection of Hazardous Picric Acid with Hydrophobic Ag Nanopillar SERS Substrates and Mechanism of Elasto-Capillarity

Download (1.72 MB)
posted on 06.01.2017 by Aron Hakonen, FengChao Wang, Per Ola Andersson, Håkan Wingfors, Tomas Rindzevicius, Michael Stenbæk Schmidt, Venugopal Rao Soma, Shicai Xu, YingQi Li, Anja Boisen, HengAn Wu
Picric acid (PA) is a severe environmental and security risk due to its unstable, toxic, and explosive properties. It is also challenging to detect in trace amounts and in situ because of its highly acidic and anionic character. Here, we assess sensing of PA under nonlaboratory conditions using surface-enhanced Raman scattering (SERS) silver nanopillar substrates and hand-held Raman spectroscopy equipment. The advancing elasto-capillarity effects are explained by molecular dynamics simulations. We obtain a SERS PA detection limit on the order of 20 ppt, corresponding attomole amounts, which together with the simple analysis methodology demonstrates that the presented approach is highly competitive for ultrasensitive analysis in the field.