Portable SERS Detector for Simultaneous Detection of Tracelevel

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: 1 R 43 ES 022884 -01 A 1 Project Period of Performance: 05/01/2015 – 10/31/2015

The Problem and The Solution v Problem: Groundwater and soils at Superfund sites are contaminated with polyaromatic hydrocarbon (PAH) compounds at trace levels, 16 are EPA priority PAHs v Current methods § Require samples sent to laboratory § Field tests lack required sensitivity v Solution: Agiltron uses Surface Enhanced Raman Spectroscopy (SERS) in a unique way to detect these PAHs in water at 0. 1 ppb levels v Our innovation: use a hydrophobic partition layer to extract PAHs directly from water sample for rapid ultrasensitive detection v Results show the potential to achieve detection limits below the target level of 0. 1 ppb.

Raman and SERS Technology v Raman spectroscopy identifies unknown molecules by their unique chemical bonding structure – routine at bulk concentrations v Measured Analyte SERS spectrum is compared to library spectra v Spectral match identifies analyte; Intensity proportional to concentration v SERS extends the method to trace level detection (ppb) v Signal enhanced by up to 108 due to strong local plasmonic electric fields formed adjacent to nanostructured substrate media Probe laser Raman scattered light Analyte samples on SERS media

Agiltron’s SERS Based Solution v Adaptation of Pin. Pointer™ Raman spectrometer for PAH detection v 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 pyrene acenaphthylene fluorene anthracene naphthalene phenanthrene

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

PAH Calibration Curves Pyrene Indeno(1, 2, 3 -cd) pyrene 2 nd Derivative Phenanthrene 975 970 965 960 Raman Shift (cm-1) 955 980 960 Raman Shift (cm-1) 940 1190 1185 1180 1175 1170 1165 Raman Shift (cm-1) Peak Area 980 Peak Area Phenanthrene conc. (ppb) y = 0. 2452 x + 3. 0497 R 2 = 0. 9425 Log value of conc. (ppb) Pyrene conc. (ppb) y = 0. 048 x + 0. 5097 R 2 = 0. 8966 Log value of conc. (ppb) Indeno(1, 2, 3 -cd)pyrene conc. (ppb) y = 0. 049 x + 0. 922 R 2 = 0. 907 Log value of conc. (ppb)

Validation on Portable Benchtop Raman System pyrene indeno(1, 2, 3 -cd) pyrene Laser: 785 nm, 25 m. W Integration time: 10 s Ag. NF phenanthrene

Summary v Synthesis of a alkane-thiol based hydrophobic partition layer on silver nanoparticle SERS substrates was optimized v Excellent signal to noise ratio SERS spectra were obtained for all 16 target PAHs to construct a searchable library of spectra v Calibration curves were constructed successfully for 3 PAHs with limits of detection of 0. 1 ppb and potentially lower v Time resolved SERS signals show effective extraction of waterborne PAHs For More Information Contact: Wayne A. Weimer, Ph. D. T: 781 -935 -1200 wweimer@agiltron. com