Inkjet-printed paper-based SERS dipsticks and swabs for trace chemical detection

Analyst. 2013 Feb 21;138(4):1020-5. doi: 10.1039/c2an36116g.

Abstract

We demonstrate a paper-based surface swab and lateral-flow dipstick that includes an inkjet-printed surface-enhanced Raman spectroscopy (SERS) substrate for analyte detection. Due to capillary-action wicking of cellulose, the paper dipstick enables extremely simple and pump-free loading of liquid samples into the detection device, and in addition provides inherent analyte concentration within the detection volume. Furthermore, the flexible nature of the paper-based SERS device also enables it to act as a swab to collect analyte molecules directly from a large-area surface; the collected analyte molecules can then be focused into a small-volume SERS-active region by lateral-flow concentration. These capabilities are unseen in today's SERS substrates and microfluidic SERS devices. Using these novel lateral-flow paper SERS devices, we achieved detection limits as low as 95 fg of Rhodamine 6G (R6G), 413 pg of the organophosphate malathion, 9 ng of heroin, and 15 ng of cocaine. Moreover, the measurements show that the technique is quantitative and is repeatable across multiple swabs and dipsticks. The results reported here may lead to ultra-low-cost portable applications in trace chemical detection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capillary Action
  • Cocaine / analysis*
  • Heroin / analysis*
  • Paper*
  • Printing*
  • Spectrum Analysis, Raman / methods*

Substances

  • Heroin
  • Cocaine