Working on the synthesis of DNA-linked gold (Au) dimers
Author: Konomi Sasaki | Major: Chemistry
My name is Konomi Sasaki, and I am majoring in chemistry with a biochemistry concentration. Over the course of the spring semester of 2022, I have been working in Dr. JinWoo Kim’s lab, as a member of the Bio/Nano Technology Group to establish a DNA-linked nanoparticle-building block. DNA-linked nanoparticle-building block is the development and analysis of programable architecture with DNA and multiple kinds of metal nanoparticles. My goal is to make progress in developing those multifunctional building blocks in various forms, such as 1D, 2D, and 3D. The building blocks can potentially be bio-imaging agents used for a cancer immunotherapy application because of the well-defined base-pairing interactions of DNA and metallic nanoparticles’ surface plasmonic response, a resonance effect due to the interaction of conduction electrons of metal nanoparticles.
My honors adviser for research is Dr. Joshua Sakon in a chemistry and biochemistry department, working mainly on protein structures and properties. The chemistry majors usually perform their research in the chemistry department under their adviser, but Dr. Sakon introduced me to Dr. Kim and other Ph.D. candidates working with him in a biological and agricultural engineering department since I was very interested in the effects and functions of DNA including the relationship between DNA and metallic particles and its physiochemical properties which can be helpful in the medical field.
The foundation of generating the DNA-programmable nanoparticle building blocks includes the fields of DNA computation, DNA-guided self-assembly, and nanoparticles in general. The programmable DNA and the anisotropic nature of nanoparticles can be exploited to integrate nanoparticles into nanostructures of various sizes and shapes. These structures can provide a variety of functions, including the plasmonic functionality of the linked metallic nanoparticles. Engineering the transformation of a large number of discrete nanoparticles into a single multifunctional nanoscale structure with specific physical, chemical, or biological properties has the potential to revolutionize a wide range of research fields, from optoelectronics and nanophononics to nanomedicine. The possibility of various nanoparticle compositions within nanocomposite structures allows for a complementary combination of multiple imaging and sensing modalities’ properties to provide more accurate diagnosis data.
This project began with the development of 1D and 2D structures using the smallest anisotropically mono-functionalized units. To make those building blocks, I followed the previous study of programmable “one step at a time” DNA conjugation for nanoparticle-building blocks using an electrostatic technique with a silica gel, published by Dr. Kim. He and his colleagues successfully made 1D and 2D structures, but there were some issues with the feasibility of the method and materials. Nobody, including himself has been able to synthesize the same structures in the same way as conducted in the study for about ten years. Therefore, my mentor, a Ph.D. candidate at the time, and I needed to find out what caused it not to work and what had to be modified. This was the most challenging part, and it took time to figure out what we should develop in making the blocks. After lots of literature studies and several trials, we could make DNA-linked gold (Au) dimers. We chose Au nanoparticles because it was used in the previous study. Ultimately, this research aims to develop programmable 3D DNA-programmable nanoparticle building blocks using different metallic nanoparticles, such as silver, copper, and iron, based on the 2D mono-functionalized Au unit of building blocks we just developed.
Through this research opportunity supported by Honors College, I have been able to realize my interest and passion for research in biochemical and engineering fields. I also learned how important it is to work with other researchers. I could never accomplish this project by myself. My mentor and advisers have always helped me gain the necessary knowledge and laboratory skills throughout this semester. I would like to continue learning and exploring new things with them.