Using Single Molecule Spectroscopy to Analyze Organic Dye Fading

The preservation of artwork is often limited by the fragility of its medium; conservators must constantly be working to counteract the forces of nature. One example is the gradual fading of organic dyes in paintings, leading to a loss of their color and vitality. As a chemist, I want to get an understanding of the process of dye fading by studying the effects of exposing them to their natural friend & foe, light.

My research project for the summer, advised by Professor Wustholz, will use Single Molecule Spectroscopy (SMS) to look at individual dye molecules and study their physical properties. More specifically, my research will study the properties of lake mordant pigments such as purpurin lake and alizarin lake in oil, which creates an environment that best matches an oil painting. Previous research in my lab has studied these molecules or similar molecules but in a solution that did not contain oil. My goal is to collect data on these molecules in oil and compare them to previous research conducted in my lab.

My methodology involves using fluorescence microscopy of single molecules to get an understanding of how they are responding to being bombarded by light. Sometimes, the molecules are in one quantum state where they are “on” or fluorescing, and sometimes they are “off” or not fluorescing. I can measure the oscillations or “blinking” between these on and off states and use the data to generate mathematical models that explain this behavior. I can also use Monte Carlo statistical simulations to generate other models and compare them to the models I have generated based on the data. All in all, I hope to find a way to make equations that can describe the photo-physics of dye fading accurately.

About me: I am a Junior Chemistry Major here at the College.  I spend some of my free time playing for the W&M Middle Eastern Music Ensemble and volunteering at the Williamsburg Hospice House. My current plan is to go medical school one day but I wanted to do research full time over the summer to get an better understanding of that career as well. I am very grateful for receiving the Charles Center Scholarship and I am looking forward to what summer research will bring.

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