Advisor Information
Alexey Krasnoslobodtsev
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
3-3-2017 12:30 PM
End Date
3-3-2017 1:45 PM
Abstract
Detection and monitoring of disease biomarkers increases probability of successful disease treatment. Surface enhanced Raman scattering (SERS) has several advantages over conventional readout strategies utilized in detecting immunoassays. SERS provides a method for chemical characterization based on molecular vibrational spectra. Raman signals are typically weak and need to be enhanced. This can be done using plasmons in nanoparticles of noble metals, we use gold (Au). Molecules with known spectra, Raman reporter molecules (RRM), can be adsorbed to Au nanoparticles. This enhances the Raman signal of the RRM when illuminated by a laser of optimal wavelength. Adding antibodies to nanoparticles modified with this method can then provide a means for finding hard to detect disease biomarkers. The focus of this research is the effects to the Raman signal by varying the nanoparticle modification process. We look at the effects of adding PEG molecules to Au nanoparticles and how Raman signals are affected by the laser used to take measurements. RRM type, nanoparticle size, and PEG amounts were varied. Consecutive measurements show how Raman signals change over time. We have interpreted Raman signal changes as plasmon-driven conversion of RRMs as well as desorption of RRMs from the surface of AuNP and photodamage. We also observed catalytic photoconversion of both NBT and ABT to diazobenzene suggesting that AuNP can act as catalysts in complex reactions. Additionally, we discovered a novel pathway of converting amine substituted benzene to carbon wires as indicated by appearance of the Raman peak at 2130 cm-1.
Improving SERS-based readout strategy for biomarker detecting immunoassays
Dr. C.C. and Mabel L. Criss Library
Detection and monitoring of disease biomarkers increases probability of successful disease treatment. Surface enhanced Raman scattering (SERS) has several advantages over conventional readout strategies utilized in detecting immunoassays. SERS provides a method for chemical characterization based on molecular vibrational spectra. Raman signals are typically weak and need to be enhanced. This can be done using plasmons in nanoparticles of noble metals, we use gold (Au). Molecules with known spectra, Raman reporter molecules (RRM), can be adsorbed to Au nanoparticles. This enhances the Raman signal of the RRM when illuminated by a laser of optimal wavelength. Adding antibodies to nanoparticles modified with this method can then provide a means for finding hard to detect disease biomarkers. The focus of this research is the effects to the Raman signal by varying the nanoparticle modification process. We look at the effects of adding PEG molecules to Au nanoparticles and how Raman signals are affected by the laser used to take measurements. RRM type, nanoparticle size, and PEG amounts were varied. Consecutive measurements show how Raman signals change over time. We have interpreted Raman signal changes as plasmon-driven conversion of RRMs as well as desorption of RRMs from the surface of AuNP and photodamage. We also observed catalytic photoconversion of both NBT and ABT to diazobenzene suggesting that AuNP can act as catalysts in complex reactions. Additionally, we discovered a novel pathway of converting amine substituted benzene to carbon wires as indicated by appearance of the Raman peak at 2130 cm-1.