Sweet Relief: How Sugar May Help Reverse Climate Change

This is one of those stories that made me go “WOW that’s cool!” I know, I know, I’m a giant nerd. Also, I’m a biologist not a chemist, so I hope I manage to do it justice.

In a paper published in the Journal of the American Chemical Society a couple of weeks ago a multi-national team of chemists showed how a sugary crystal could soak up CO2 from the atmosphere.

The general principle behind their experiments was not novel. A number of groups have been using porous metal-organic frameworks (MOFs) to specifically remove CO2 from the air, however in all cases the MOFs were either made of petrochemical byproducts or involved the use of toxic chemicals. Obviously neither of these things is good when your ultimate goal is to clean up the planet.

But Jeremiah Gassensmith and friends have generated a carbon-neutral and toxin-free MOF called CD-MOF-2 (not super-catchy). CD-MOF-2 is made up of γ-cyclodextrin; a ring structure comprising eight sugar moieties similar to those found in starch (a.k.a. amylose). Six of these rings are then assembled into a cube-like structure that is able to stably interact with CO2. Importantly, γ-cyclodextrin is produced microbiologically from starch (i.e. plant material) and the CD-MOF-2 crystal is formed by water, methanol, or ethanol precipitation. Very green.

Well, actually it’s not green…it’s yellow/red. In order to figure out how CD-MOF-2 was able to remove CO2 from the air the authors of this study incorporated a pH indicator into the crystals. When methyl red (for the chemists out there methyl red is a zwitterionic azobenzene-based pH indicator) was diffused into the pores of CD-MOF-2 the crystals formed were yellow. However after to exposure to CO2 they turned red. This suggested that an acidic substance was accumulating, which turned out to be carbonic acid. Furthermore, this process was reversible and the crystals could be reused repeatedly without suffering any “fatigue”.

This discovery will likely lead to the development of novel technologies for the removal of atmospheric carbon dioxide, and therefore represents an ingenious solution to the very real (no matter how hard the GOP tries to convince us otherwise) climate change planet earth is experiencing.

But this is not the first time cyclodextrins have come to the rescue! Hydroxypropyl β-cyclodextrin is the active ingredient in Febreeze, a household essential for those emergency situations when you didn’t quite get around to doing laundry. And for that lovely fresh scent when you did do you laundry you can thank the cyclodextrins in drier sheets that release fragrances when heated.

Cyclodextrins: Keeping the world fresh and cool.


Katie Pratt is a graduate student in Molecular Biology at Brown University. She has a passion for science communication, and in an attempt to bring hardcore biology and medicine to everyone, she blogs jargon-free at www.katiephd.com. Follow her escapades in the lab and online on Twitter.



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UPDATE: Congratulations to Carolien – this week’s winner of Mind the Gap!

About the winner: Carolien is a post-grad student from Stellenbosch University, South Africa. Trying to find ways to use nematodes in orchards as biological control agents and explaining that to people over casual dinner conversations. [Follow Carolien on Twitter]

About the prize: In addition to fame and glory beyond their wildest dreams, winners receive our new hot-off-the-presses large (15 oz) BenchFly mug to help quench their unending thirst for scientific knowledge… or coffee.



Miss a previous edition of Mind the Gap? Shame on you! Don’t worry – we’ve got you covered:

All Work and No Play Makes Katie RSI Prone

Sexual Identity and Autocrine Stimulation: Oh, To Be Teenage Yeast

On Wine, Sunburns and the Tendency of Headlines to Mislead

Which Came First: The Opossum or the Snake?

Pigeons Know a Crazy Woman When they See One

To Boldly Go Where No Worm Has Gone Before

Another One Bites the Dust: Rinderpest Eradicated

Scientists Just Wanna Have Fun (Like Uncaged Monkeys)

Mosquitoes Eating You Alive? Cheesy Feet Could be the Problem

Dirty Mouth? Clean it Up with Cancer Screening

Because in Space…It’s Always 5 O’Clock Somewhere

Curry: Now Good for Detecting Explosions, Not Just Causing Them

So You Thought Eating Poop Was Bad For You?

Are Fatty Acids the Cure for PMS?

Botanical Sleuthing Recovered Endangered Daisy





12 comments so far. Join The Discussion

  1. Priyanka

    wrote on September 28, 2011 at 2:20 pm

    Carbon Dioxide Sponge

  2. Priyanka

    wrote on September 28, 2011 at 2:21 pm

    Edible Carbon Dioxide Sponge

  3. Priyanka

    wrote on September 28, 2011 at 2:27 pm

    OR IS IT.. cyclodextrin-metal-organic framework

  4. Priyanka

    wrote on September 28, 2011 at 2:31 pm

    Edible Carbon Dioxide Candy

  5. jimbot

    wrote on September 28, 2011 at 4:46 pm

    If you eat it, does it give you gas?

  6. [email protected]

    wrote on September 28, 2011 at 4:56 pm

    That's the CO2 to methane conversion…

  7. LeBiochimiste

    wrote on September 28, 2011 at 2:32 pm


  8. [email protected]

    wrote on September 28, 2011 at 2:35 pm

    SO close!

  9. Carolien

    wrote on September 28, 2011 at 2:39 pm


  10. [email protected]

    wrote on September 28, 2011 at 2:42 pm

    We've got a winner!!

  11. proteinwrangler

    wrote on September 28, 2011 at 2:40 pm


  12. Priyanka

    wrote on September 28, 2011 at 2:40 pm

    CD-MOF 2

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