Establishment of Protocols to Measure Near-IR(NIR) Surface-Enhanced Raman Scattering (SERS) Signals of NIR Dye

Department Chair

M. Scott Goodman

Author

Justin B. Ramsey, Buffalo State CollegeFollow

Date of Award

7-2024

Access Control

Open Access

Degree Name

Forensic Science, M.S.

Department

Chemistry Department

Advisor

Jinseok Heo

First Reader

Jinseok Heo

Second Reader

Sujit Suwal

Third Reader

Joonyeong Kim

Abstract

Biomedical imaging techniques are crucial for early disease diagnostics, particularly for life-threatening conditions. However, traditional methods have inherent limitations, such as restricted spatial resolution and potential risks associated with repeated exposure to ionizing radiation. Near-infrared (NIR) surface-enhanced Raman spectroscopy (SERS) presents a promising alternative due to its minimal risks and potential for high-resolution biomedical imaging. A key challenge in NIR-SERS biomedical imaging is the development of biocompatible, nontoxic SERS substrates that can be safely introduced into the human body, targeting specific cells and tissues effectively.

NIR-SERS substrates typically consist of gold nanoparticles (AuNPs) modified with biorecognition elements and reporter molecules, which exhibit strong absorption and Raman scattering signals in the NIR region. Over the past years, Suwal's lab at Buffalo State University synthesized twelve polymethine NIR dye molecules and identified three that showed superior NIR SERS performance compared to a reference dye. They utilized quick freezing-induced Au nanoparticle aggregates (QFIAA), discovered by Dr. Heo's lab, as NIR-SERS substrates.

This project aims to revisit previous protocols and validate the conclusions drawn from earlier findings. The repeatability of SERS test results may be influenced by variations in QFIAA substrates, instrumental conditions, solubility of dye molecules in solution, and AuNP aggregation, which can also vary based on dye concentration. Results indicate that the aggregation status of QFIAAs remains stable for almost a year. While there may be day-to-day variations in the absolute SERS signals of dye molecules, the relative SERS intensity order of different NIR dye molecules remains consistent across different test dates, confirming previous conclusions. Additionally, the results underscore the importance of dye solubility. Monitoring the repeatability of absorbance of certain dye molecules is critical, as those with poor solubility may precipitate over time, leading to changes in absorbance.

Comments

N/A

Recommended Citation

Ramsey, Justin B., "Establishment of Protocols to Measure Near-IR(NIR) Surface-Enhanced Raman Scattering (SERS) Signals of NIR Dye" (2024). Forensic Science Master's Projects. 12.
https://digitalcommons.buffalostate.edu/forensic_science_projects/12