Rapid screening and identification of fentanyl in drug mixtures using surface enhanced Raman spectroscopy

1. Statement of the Problem: The goal of this proposal is to develop methods for the determination of fentanyl analogs in drug mixtures by portable Raman. The impetus for this work is the increasingly common practice of adding low levels of extremely toxic fentanyl to cocaine, heroin and other drugs, endangering users and laboratory personnel. Surface enhanced Raman Spectroscopy provides a sensitive and specific way to screen for these compounds.

2. Primary activities: We will prepare a library of fentanyl spectra and mixtures using an optimized surface enhanced Raman methodology. Sample preparation involves testing seized drugs of abuse in a solution containing gold-silver nanostars and magnesium chloride. The procedure is rapid (under 10 min) and can be performed in 96 well plates. Levels of fentanyl in mixtures as low as 0.05% can be detected in heroin using portable Raman systems.

3. Analysis: Using DFT, we will determine the chemical identity of key peaks useful in analysis of fentanyl analogs. The collected data will also be used to prepare a software solution to permit spectral deconvolution of drug mixtures containing fentanyls, illicit drugs and diluents. An initial training set of individual spectra will be used to develop methods for detection of mixtures containing fentanyl via machine learning and chemometric approaches.

4. Service Area: This effort will be performed by Florida International University (FIU) at the research lab of Dr. Bruce McCord. Assisting in this work will be professor Alex Mebel (FIU) who will assist in calculations for spectral peak assignment and Professor Peter Harrington (Ohio University) who will assist with data analysis and expert systems. Validation and forensic oversight will be performed in collaboration with the FDA Forensic Chemistry Center.

5. Deliverables/beneficiaries: A rapid and sensitive method for identifying fentanyl analogs in mixtures by portable Raman and SERS will be delivered along with a spectral library.  Manuscripts will include reports on fentanyl analog detection, mixture deconvolution, and statistical tools. Results will also be presented at the AAFS and SOFT meetings and by webinar. The primary beneficiaries of this project will be crime laboratories with portable Raman systems who will have a rapid and specific method for screening and detection of low levels of fentanyl in mixtures. CA/NCF