Raman and Surface Enhanced Raman Spectroscopy for Forensic Analysis: Case Studies on the Identification of Illicit Substances and Artist Pigments

<p>Raman spectroscopy is an effective tool for detecting trace amounts of material by fingerprint-like vibrational spectra. At times, the weak intensity of Raman scattering can make it difficult to distinguish trace materials. This shortcoming is addressed by surface‐enhanced Raman spectroscopy (SERS), which produces strong signal enhancements when target compounds are near metal nanoparticles. For the first part of this thesis, the identification of fentanyl and carfentanil, main culprits in the opioid epidemic, was done using normal Raman and the SERS spectroscopy. As an aid in the assignment of the spectral lines, a computational model was built using Density Functional Theory (DFT). The enhancement factor (E_F) obtained in this experiment is ≥ 1.6 x 10⁵. The use of a paper-based substrate impregnated with silver nanoparticles for the detection of trace quantities of fentanyl alone, and as an adulterant in heroin and cocaine, was investigated. In addition, intensity ratios of diagnostic peaks associated with each substance were fitted to a Langmuir isotherm calibration model and used for quantitative analysis of fentanyl in heroin mixtures. Linearity was observed at < 6% fentanyl, a significant finding that is consistent with concentrations found in drugs seized during law enforcement efforts. For trace quantities of fentanyl in cocaine, where it identified at a lower limit of 500 ng/mL in mixtures. Linear relationships were established between intensity and concentration for diagnostic peaks associated with fentanyl and cocaine. For the second part of this thesis, the applicability of normal Raman and SERS are presented in the context of a museum setting. The applicability of confocal and portable Raman is presented through the identification of : red pigments found in El Anatsui’s <em>Bleeding Takari II;</em> identification of the gouaches used by Henri Matisse in the <em>Jazz</em> album; and identification of the paints used by Jackson Pollock in <em>Number 1A, 1948</em>.</p>

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry

Grantor

The Graduate School and University Center of The City University of New York

Year dc:date.available

2019

Author dc:creator

• Haddad, Abed

Advisor dc:contributor.advisor

• John Lombardi

Committee members dc:contributor.committeemember

• Louis Massa
• Glen Kowach

• Analytical Chemistry
• Applied Statistics
• Contemporary Art
• Materials Chemistry
• Modern Art and Architecture
• Raman
• SERS
• Forensics
• Opioids
• Cultural Heritage
• Pigments

Repository record dc:identifier

https://academicworks.cuny.edu/gc_etds/3271

OAI identifier oai:identifier

oai:academicworks.cuny.edu:gc_etds-4176