Diagonal Samples. In Art of Science

Caption: When biomolecules come into contact with a nanoparticle, they surround the particle, which impacts the movement of the nanoparticle as well as the structure of the biomolecule, sometimes permanently.
Participant category: Undergraduate student
Departments: Chemistry and Biochemistry, Chemical Engineering

Three 1.5mL centrifuge tubes rest inside a bright green plastic sample rack, taking up three of the closest slots to the camera that are available. The tubes are in focus, and each contain approximately 1mL of liquid. Indistinct writing in thin permanent marker is present on the sides and caps of all three tubes. The rest of the rack is empty; rows of empty slots extend backwards into the image, becoming blurred the further back they reach. The sample rack rests on top of a white machine: an Ultraviolet-Visible (UV-Vis) spectrometer. These samples are to be analyzed using the UV-Vis in the near future. A crumpled, brown paper towel falls off the left side of the image; it was used to help dry the cuvettes used in the UV-Vis. A laminated paper with black text printed on it is visible on top of the UV-Vis. The background is blurred, but shows a lab bench covered in various devices, tubes, boxes, and experiments in progress. Also in the background are a line of white cabinets with vertical windows that reflect the white lab lighting and hint at the many supplies stored in this room. The entire picture appears to be tilted approximately 15 degrees clockwise from horizontal, which puts everything at a slant and creates very energetic diagonal movement throughout the image.

Science behind image description: Relationships are complex. Studying them can be remarkably complex as well, especially when the relationships are essentially invisible! Hence, studying the nano-scale relationships between metal oxides and biomolecules is no easy feat. In this picture, an Ultraviolet-Visible spectrometer is being used to analyze three samples of nucleotides that have been exposed to titanium dioxide nanoparticles. Other methods are used in conjunction with the UV-Vis, including Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, High Performance Liquid Chromatography (HPLC), and X-Ray Diffraction (XRD). All these techniques combined give us an idea of what happens when a biomolecule (such as a nucleotide, protein, or amino acid) comes into contact with a nanoparticle (such as titanium dioxide or hematite). Why are we using all these techniques and putting in so much effort to characterize these nano-scale relationships? Why are they important? It turns out that nanoparticles and biomolecules interact very frequently with each other, and those interactions can have an important effect on pollution movement, ecosystem health, and human wellbeing. When biomolecules come into contact with a nanoparticle, they form a corona around the particle, encompassing it. This impacts the way the nanoparticle moves through a system, which means it can end up in places that it perhaps shouldn’t be. For example, nanoparticles in a human bloodstream can be transported to the heart, where they accumulate and can cause a variety of health issues. The corona also impacts the biomolecules: upon interacting with nanoparticles, the structure of the biomolecules can be altered. Sometimes that alteration is permanent, even after the biomolecule is no longer interacting with the nanoparticle. This has implications for the functionality of biomolecules in the presence of nanoparticles, which is concerning if the change in functionality is detrimental to the health of the system. We study these relationships so that we can determine what issues may arise from nanoparticle-biomolecule interactions, and how we can avoid them. We also study them so that we can expand our understanding of the world we inhabit. What we learn from our research will inform us how to better interact with our environments, and will ultimately make us better citizens of planet Earth.