Plants and Particles: The Greener Side of Carbon Dots

       Good afternoon, ladies and gentle scientists! Today, we are going to look at the smaller sides of life—and by small, I mean less than ten nanometers in size. This week we are examining another particle that is revolutionizing the scientific field: the carbon dot.

Discovered in 2004 by Xiaoyou Xu and his team, carbon dots are tiny carbon-based nanoparticles that are less than 10 nanometers in size. These microscopic particles are relevant because they absorb light and then emit it at a longer wavelength. These carbon dots have received significant attention for several reasons:

1. Certain light-emitting substances go through a process called photobleaching, where they lose their ability to emit light after being exposed to it for too long. Yet, carbon dots resist photobleaching, which allows them to glow brightly for prolonged periods without fading, no matter how long they are exposed.

2. Carbon dots have good biocompatibility, meaning they can reside in living organisms without causing any harm, which makes them incredibly useful for medical procedures.

3. Carbon dots have stable physicochemical characteristics, meaning they can keep their same properties—such as shape, size, reactivity, and solubility—for long amounts of time.

Due to these properties, carbon dots have been used in a variety of scientific procedures, including medicine and chemistry. For example, they have been used in disease treatment, ion and molecular detection (the process by which molecules and ions are identified in a solution to figure out its properties), bioimaging (the process by which internal structures of organisms are identified), and measuring the acidity and alkalinity of mixtures. It is extremely useful in multiple areas of science and has revolutionized the scientific field in all sorts of ways. However, like any part of science, it comes with its setbacks.

To understand these setbacks, we first have to discuss a crucial part of the carbon dot called the precursor. To put it simply, a precursor in a carbon dot is any carbon-containing material that can be used to make this substance. Yet many of these precursors, such as nitrogen and sulfur, can be harmful, nonrenewable, and unreliable. Scientists knew that these carbon dots needed other types of precursors to function sufficiently. From there, scientists decided to turn to green methods—or more sustainable methods. One method that especially caught their eye was the method of incorporating herbal medicine as a precursor, creating a substance known as HM-CDs. Herbal medicine was chosen due to its natural abundance in the world, its simple and efficient preparation, and its biocompatibility.

The place it made the biggest impact on is the area of theranostics. This refers to the approach in medicine where the diagnosis and treatment of conditions within the human body happen together. Carbon dots worked well in this area due to their microscopy, long-lastingness, and ability to emit large amounts of light or fluorescence. Yet once HM-CDs came into the equation, theranostics soared to higher levels than ever before. Because of how biocompatible and reliable these precursors were, carbon dots could finally be used in abundant amounts, and scientists have been using them ever since.

Anyway, to end this off—just a few personal thoughts. First off, I was incredibly excited to try learning about herbal medicine, as the scientist who will be mentoring me through the Lumiere research program this summer specializes in this area. It also helps that the first area of herbal medicine I decided to endeavor into was microscopic (as I adore microbiology).

Yet on the subject of the actual article, this piqued my interest due to just the brilliance of it. After all, who would have thought light could be created through plants? The more I read these articles, the more I come to appreciate how bewildering yet fascinating science truly is. Every day, scientists test the limits of the world and come through with breakthroughs such as these.

This also excited me because recently I have gotten a bit invested in climate change, and the idea that renewable sources such as these are already being created gives me hope for a future where all sources of electricity, heat, and transportation will be renewable.

Anyway, sorry for the short post—I got home late today and didn’t have a lot of time to write. Exams are in two weeks, so I may not have as much time to go through these articles. Expect shorter articles for a little while. I may go a bit deeper into herbal medicine next week, as this fascinates me—but we shall see.

So to end this post, a question: what other sources do you think herbs could be beneficial in?

As always, I hope you learned something new, and I will see you next week!