Week 1:
Before this past week, when someone said “Raman” my mind would immediately go to ramen noodles that my son loves to eat. I am working with Dr. Oara Neumann and Mary Bajomo in Naomi Halas lab. The Raman we are working with is an awesome instrument with two lasers source: 785 nm (a near-infrared excitation source that can eliminate sample fluorescence) and 633 nm. We use the Raman instrument to probe the chemical structure in molecules. The probed molecules have a unique set of energy levels that depends on their unique atomic and molecular structure like the mass of atom, the strength of the bond, the conformation, as well as the specific molecular arrangements. The atoms in the molecular arrangement can compress or stretch along the axes of a bond, or can bend symmetrically or asymmetrically; yields vibrations, which occur at a unique frequency. The vibrational modes of a molecule give rise to a spectrum that provides unique information about any molecules. To enhance the Raman signal we are using Au nanoparticles. The technique is called Surface-enhanced Raman scattering and we are using it to identify/determine the polycyclic aromatic hydrocarbons (PAHs) contaminants in water. PAHs are widespread pollutants that are known to be carcinogenic, mutagenic, and teratogenic (meaning they can cause malformations of a fetus during development). There are a few techniques that are used to detect PAHs in drinking water, but they are costly and time consuming. The research being done in Naomi Halas lab will contribute to finding a portable, accurately, and cost-efficient way of detecting PAH’s.
Awesome Raman Spectrometer with microscope
Acquire SERS substrate baseline. The substrate contains: quartz functionalized with PVP (poly vinylin pyridine) and Au nanoparticles.
Add PAHs on the SERS substrate and perform the SERS measurements
Looking forward to week 2! I will get to make and run the samples!! So much to learn!
Fun fact: Did you know they can use Surface-enhanced Raman Scattering to differentiate between Influenza and Covid (both RNA viruses) even at low concentrations.
Hey Julia! This is awesome! You are getting to work with lasers. It seems like you all dove right into it from day 1. I remember the professor that presented to us talking about some of the concepts that you are referring to in your blog. In essence, our end goal is the same as you all. To find a cost effective solution to our current problem. What makes this entire process interesting is the cost benefit analysis component that they are including as well. Please keep us posted on your project. Those malformations in the fetus sound scary!