Portable SERS Detector for Simultaneous Detection of Trace-level Polycyclic Aromatic Hydrocarbons on Superfund Sites Wayne Weimer (PI) and Monika Wilson, Agiltron Inc. Professor Lili He, University of Massachusetts Amherst SBIR Phase I Program Officer: Heather F. Henry Grant Number: 1R43ES A1 Project Period of Performance: 05/01/2015 – 10/31/2015

The Problem and The Solution  Problem: Groundwater and soils at Superfund sites are contaminated with polyaromatic hydrocarbon (PAH) compounds at trace levels, 16 are EPA priority PAHs  Current methods  Require samples sent to laboratory  Field tests lack required sensitivity  Solution: Agiltron uses Surface Enhanced Raman Spectroscopy (SERS) in a unique way to detect these PAHs in water at 0.1 ppb levels  Our innovation: use a hydrophobic partition layer to extract PAHs directly from water sample for rapid ultrasensitive detection  Results show the potential to achieve detection limits below the target level of 0.1 ppb.

Raman and SERS Technology  Raman spectroscopy identifies unknown molecules by their unique chemical bonding structure – routine at bulk concentrations  Measured Analyte SERS spectrum is compared to library spectra  Spectral match identifies analyte; Intensity proportional to concentration  SERS extends the method to trace level detection (ppb)  Signal enhanced by up to 10 8 due to strong local plasmonic electric fields formed adjacent to nanostructured substrate media Probe laser Analyte samples on SERS media Raman scattered light

Agiltron’s SERS Based Solution  Adaptation of PinPointer™ Raman spectrometer for PAH detection  Development of hydrophobic partition layer to extract PAH from water sample for immediate identification and quantitation

Library Construction (1) SERS Spectra of 7 Priority PAHs phenanthrene naphthalene anthracene fluorene acenaphthylene acenaphthene pyrene

dibenz(ah)anthracene chrysene benzo[k]fluoranthene benzo[ghi]perylene benzo[a]pyrene benzo[b]fluoranthene benzo[a]anthracene indeno[1,2,3-cd]pyrene fluoranthene Library Construction (2) SERS Spectra of 9 Priority PAHs

PAH Calibration Curves PyreneIndeno(1,2,3-cd) pyrenePhenanthrene Log value of conc. (ppb) Phenanthrene conc. (ppb) Pyrene conc. (ppb)Indeno(1,2,3-cd)pyrene conc. (ppb) Raman Shift (cm -1 ) Raman Shift (cm -1 ) Raman Shift (cm -1 ) Peak Area y = 0.049x R 2 = y = x R 2 = y = 0.048x R 2 = nd Derivative

Validation on Portable Benchtop Raman System Laser: 785 nm, 25 mW Integration time: 10 s pyrene indeno(1,2,3-cd) pyrene phenanthreneAgNF

Summary  Synthesis of a alkane-thiol based hydrophobic partition layer on silver nanoparticle SERS substrates was optimized  Excellent signal to noise ratio SERS spectra were obtained for all 16 target PAHs to construct a searchable library of spectra  Calibration curves were constructed successfully for 3 PAHs with limits of detection of 0.1 ppb and potentially lower  Time resolved SERS signals show effective extraction of waterborne PAHs For More Information Contact: Wayne A. Weimer, Ph.D. T: