Author(s): Quinn Griffin
Mentor(s): Hao Jing, Department of Chemistry and Biochemistry
AbstractGold nanobipyramids are anisotropic nanoparticles with strong surface enhanced plasmon resonance absorbance in the visible and near IR spectrums. The strong electric field enhancements and absorption properties make these particles good candidates for surface enhanced Raman spectroscopy. Small AuNBPs with a high purity were synthesized successfully. These particles will be used to create thin films on silicon and will be used for SERS detection of low concentrations of artificial sweeteners, PFAS, and PCBs in water.
Audio TranscriptMy name is Quinn Griffin, and this is my project on the synthesis of small gold nanobipyramids for surface enhanced Raman spectroscopy detection of persistent organic pollutants. I’m in the department of chemistry and biochemistry. My advisor for this project was Dr. Hao Jing.
First, we need to go over some background. Gold nanoparticles, because of a property called surface plasmon resonance are able absorb and reemit light at various wavelengths. Gold nanobipyramids are a particular type of gold nanoparticle that have an extremely high absorption and emission spectra in the visible and infrared regions. Raman spectroscopy is a good method of identifying molecules that uses infrared light. Persistent organic pollutants are found at extremely low concentrations in human water ways and yet they still cause harm to our health. We hope to use our gold nanobipyramids to enhance the infrared signals given off during Raman spectroscopy to allow us to detect persistent organic pollutants at incredibly low concentrations.
Now for our research goals. First, we need to synthesize small gold nanobipyramids. Second, we need to use these nanobipyramids to create thin films. And third we need to use these thin films as substrates for Raman spectroscopy of persistent organic pollutants. We plan to make Raman measurements to various persistent organic pollutants. But first, we will be starting with making Raman measurements of artificial sweeteners to ensure we fully understand the process and procedure prior to working with these more dangerous materials. Then we will be working PFAS, or perfluorinated alkyl substances. Finally, we’ll be working with PCBs, polychlorinated biphenyls. For each substance we will first start at a high concentration. As we’re able to successfully detect the molecules at the high concentrations, we will begin to dilute the solutions to lower concentrations until we can find the lower limit of detection.
Next, we’ll be discussing the progress that we’ve already made. First, we purchased all the supplies necessary for the project. This includes the supplies to create the gold nanobipyramids, the supplies needed for the Raman measurements, and the persistent organic pollutants themselves. We’ve successfully created small gold nanobipyramids. However, we still need to increase the purity. As you can see in the far-right image, there are still spheres present in our solution. When creating thin films, we want very high uniformity in the nanoparticles because we want to make consistent, repeatable thin films. Finally, we’re currently working on resuspending the gold nanobipyramids into various surfactants. The different types of surfactants and varying concentrations of each one will determine the distance between each particle in the thin films.
We’re now moving on to our future work. Once we’ve resuspended our particles in various surfactants, we will work on creating thin films via dip coating. Once we’ve successfully made thin films out of the gold nanoparticles, we will begin making surface enhanced Raman measurements or SERS of artificial sweeteners. Following successful identification of the artificial sweeteners at low concentrations, we will begin working with persistent organic pollutants like PFAS and PCBs. If the minimum concentration to detect PCBs and PFAS in water is low, this method could prove incredibly useful for detecting these dangerous pollutants in human water ways.
For acknowledgments, I would like to thank Au Lac Nguyen and Dr. Hao Jing for their support and guidance throughout the entire project. I would like to thank the Office of Student Creative Activities and Research for funding the project. And finally, I would like to thank the Department of Chemistry and Biochemistry for all their support
These are my citations, thank you for listening.
First, we need to go over some background. Gold nanoparticles, because of a property called surface plasmon resonance are able absorb and reemit light at various wavelengths. Gold nanobipyramids are a particular type of gold nanoparticle that have an extremely high absorption and emission spectra in the visible and infrared regions. Raman spectroscopy is a good method of identifying molecules that uses infrared light. Persistent organic pollutants are found at extremely low concentrations in human water ways and yet they still cause harm to our health. We hope to use our gold nanobipyramids to enhance the infrared signals given off during Raman spectroscopy to allow us to detect persistent organic pollutants at incredibly low concentrations.
Now for our research goals. First, we need to synthesize small gold nanobipyramids. Second, we need to use these nanobipyramids to create thin films. And third we need to use these thin films as substrates for Raman spectroscopy of persistent organic pollutants. We plan to make Raman measurements to various persistent organic pollutants. But first, we will be starting with making Raman measurements of artificial sweeteners to ensure we fully understand the process and procedure prior to working with these more dangerous materials. Then we will be working PFAS, or perfluorinated alkyl substances. Finally, we’ll be working with PCBs, polychlorinated biphenyls. For each substance we will first start at a high concentration. As we’re able to successfully detect the molecules at the high concentrations, we will begin to dilute the solutions to lower concentrations until we can find the lower limit of detection.
Next, we’ll be discussing the progress that we’ve already made. First, we purchased all the supplies necessary for the project. This includes the supplies to create the gold nanobipyramids, the supplies needed for the Raman measurements, and the persistent organic pollutants themselves. We’ve successfully created small gold nanobipyramids. However, we still need to increase the purity. As you can see in the far-right image, there are still spheres present in our solution. When creating thin films, we want very high uniformity in the nanoparticles because we want to make consistent, repeatable thin films. Finally, we’re currently working on resuspending the gold nanobipyramids into various surfactants. The different types of surfactants and varying concentrations of each one will determine the distance between each particle in the thin films.
We’re now moving on to our future work. Once we’ve resuspended our particles in various surfactants, we will work on creating thin films via dip coating. Once we’ve successfully made thin films out of the gold nanoparticles, we will begin making surface enhanced Raman measurements or SERS of artificial sweeteners. Following successful identification of the artificial sweeteners at low concentrations, we will begin working with persistent organic pollutants like PFAS and PCBs. If the minimum concentration to detect PCBs and PFAS in water is low, this method could prove incredibly useful for detecting these dangerous pollutants in human water ways.
For acknowledgments, I would like to thank Au Lac Nguyen and Dr. Hao Jing for their support and guidance throughout the entire project. I would like to thank the Office of Student Creative Activities and Research for funding the project. And finally, I would like to thank the Department of Chemistry and Biochemistry for all their support
These are my citations, thank you for listening.
One reply on “On the synthesis of small gold nanobipyramids for surface enhanced Raman spectroscopy detection of persistent organic pollutants”
Thank you for this clear explanation of your work. Will you be continuing with the next steps?