Porous Material with Gated Nanopores

  • Author: Angewandte Chemie International Edition
  • Published Date: 16 April 2021
  • Copyright: Wiley-VCH GmbH
thumbnail image: Porous Material with Gated Nanopores

Covalent organic frameworks (COFs) are porous crystalline networks made from organic building blocks. Such porous materials can, for example, be used to encapsulate guest molecules and release them upon a certain stimulus. This stimulus can, e.g., be light—a manual gating mechanism. However, autonomous gating could be even more useful. Here, the stimulus is a concentration change of a "reporter chemical" close to the site where the guest molecules need to be released. One potential strategy towards autonomous gating is using a protein as the "gate" which undergoes a conformational change upon binding to the reporter chemical.

Takuzo Aida, University of Tokyo, Japan, and RIKEN Center for Emergent Matter Science, Wako, Japan, Kou Okuro, University of Tokyo and University of Hong Kong, China, and colleagues have developed a COF with hexagonally packed nanopores (pictured in blue) that contains multiple guanidinium groups. These functional groups can form salt bridges with biopolymers such as proteins, and thus, bind them to the COF. The team prepared the COF from an azide-substituted analogue via a copper‐catalyzed click reaction with propargyl guanidine.

Then they used this "bio-adhesive" COF together with a protein-based gate (pictured in grey). The "gate" gives the COF the ability to open its nanopores in the presence of a reporter chemical and release guest molecules (pictured in pink). Calmodulin, a protein known to change its conformation upon the selective binding of Ca2+, was chosen as the gating component, and sulforhodamine B was used as a model guest.


Guest molecules are released from the nanopores in response to an increased Ca2+ concentration. The researchers believe that this approach can be used, e.g., for chemotherapy of bone diseases with reduced side effects. In these diseases, the local concentration of Ca2+ at the diseased sites is high and the guest molecules can be released in a targeted manner.



Article Views: 2320

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH