Carbon Quantum Dots in Your Favorite Color

Citizen scientist extraordinaire [Thought Emporium] put out a new video about colorful quantum dots which can be seen below the break. Quantum dots are a few nanometers wide and you can tell which size they are by which color they fluoresce. Their optical and electrical properties vary proportionally with size so red will behave differently than purple but we doubt they will taste like “cherry” and  “grape.” Let’s not find out. This makes sense when you realize that a diamond will turn into black powder if you pulverize it. Carbon is funny like that.

[Thought Emporium] uses the video for two purposes. The first is to demonstrate the process he uses to make different size quantum dot in his home lab. The second purpose is to implore the scientific community, in general, to take better care when publishing scientific papers. A flimsy third reason is to show that the show must go on. Partway through, all the batteries for his light were dead so he hastily soldered a connection for his benchtop power supply.

We’ve mentioned [Thought Emporium] a few times before. Another of his carbon-based experiments involved graphene creation. How about magnetic DNA extraction? [Thought Emporium] did that too. If you can’t get enough magnets, how about implanting one?

13 thoughts on “Carbon Quantum Dots in Your Favorite Color

    1. Not to worry. It’s not Nature – nature but Nature – scientific reports. It’s a bit confusing since nature is both a publisher and a journal. While sc. report is considered pretty good it’s no way near “the nature” or so to say.

  1. That’s pretty neat that you can produce a fluorescent material so easily, but (at least in this video) he does not indicate how he determines they are *really* quantum dots he’s producing. Given the feedstock, I wonder if it’s actually producing something more mundane, like anthracene or any of a myriad other organic fluorescent dyes.

    1. Only if you want to walk around with your bare eyeballs exposed to the UV light it takes to light up the sidewalks. So instead of making the sidewalks fluoresce, requiring lots of UV light and making people appear as shadows or weirdly glowing freaks… oh, I see!

      Seriously, though, it only lights up when under UV light. Isn’t it easier to just hang regular street lighting? And safer? You know UV will slowly make the lense in your eye go cloudy, right?

  2. Good on this guy. Rarely do you see any private citizens attempting to replicate published work (I wonder how he even got access to Nature, I thought it was prohibitively expensive unless your institution has access), and as a grad student in a electronic materials lab (some of what we do is nanoparticle synthesis), I’ll definitely keep this in mind when publishing.

  3. These quantum dots are sized controlled soot? What if you took the sugar water solution, vaporize it with an ultrasonic humidifier, flow the droplets through a high temperature region, (focused laser or halogen light source) in an inert gas and captured them on filter paper? Wouldn’t the soot size be a function of droplet size and sugar concentration in the droplets?

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