Abstract
New functional materials can in principle be created using colloids that self-assemble into a desired structure by means of a programmable recognition and binding scheme. This idea has been explored by attaching ‘programmed’ DNA strands to nanometre-1,2,3 and micrometre-4,5 sized particles and then using DNA hybridization to direct the placement of the particles in the final assembly. Here we demonstrate an alternative recognition mechanism for directing the assembly of composite structures, based on particles with complementary shapes. Our system, which uses Fischer’s lock-and-key principle6, employs colloidal spheres as keys and monodisperse colloidal particles with a spherical cavity as locks that bind spontaneously and reversibly via the depletion interaction. The lock-and-key binding is specific because it is controlled by how closely the size of a spherical colloidal key particle matches the radius of the spherical cavity of the lock particle. The strength of the binding can be further tuned by adjusting the solution composition or temperature. The composite assemblies have the unique feature of having flexible bonds, allowing us to produce flexible dimeric, trimeric and tetrameric colloidal molecules as well as more complex colloidal polymers. We expect that this lock-and-key recognition mechanism will find wider use as a means of programming and directing colloidal self-assembly.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Mirkin, C., Letsinger, R., Mucic, R. & Storhoff, J. A DNA-based method for rationally assembling nanoparticles into macroscopic materials. Nature 382, 607–609 (1996)
Nykypanchuk, D., Maye, M. M., van der Lelie, D. & Gang, O. DNA-guided crystallization of colloidal nanoparticles. Nature 451, 549–552 (2008)
Park, S. Y. et al. DNA-programmable nanoparticle crystallization. Nature 451, 553–556 (2008)
Valignat, M., Theodoly, O., Crocker, J., Russel, W. & Chaikin, P. Reversible self-assembly and directed assembly of DNA-linked micrometer-sized colloids. Proc. Natl Acad. Sci. USA 102, 4225–4229 (2005)
Rogers, P. et al. Selective, controllable, and reversible aggregation of polystyrene latex microspheres via DNA hybridization. Langmuir 21, 5562–5569 (2005)
Fischer, E. Einfluss der Configuration auf die Wirkung der Enzyme. Ber. deutsch. chem. Gesell. 27, 2985–2993 (1894)
Obey, T. & Vincent, B. Novel monodisperse “silicone oil”/water emulsions. J. Colloid Interf. Sci. 163, 454–463 (1994)
Asakura, S. & Oosawa, F. On interaction between two bodies immersed in a solution of macromolecules. J. Chem. Phys. 22, 1255–1256 (1954)
Lekkerkerker, H., Poon, W., Pusey, P., Stroobants, A. & Warren, P. Phase-behavior of colloid plus polymer mixtures. Europhys. Lett. 20, 559–564 (1992)
Odriozola, G., Jimenez-Angeles, F. & Lozada-Cassou, M. Entropy driven key-lock assembly. J. Chem. Phys. 129, 111101 (2008)
König, P., Roth, R. & Dietrich, S. Lock and key model system. Europhys. Lett. 84, 68006 (2008)
Saunders, B. & Vincent, B. Microgel particles as model colloids: theory, properties and applications. Adv. Colloid Interf. Sci. 80, 1–25 (1999)
Stöber, W., Fink, A. & Bohn, E. Controlled growth of monodisperse silica spheres in micron size range. J. Colloid Interf. Sci. 26, 62–69 (1968)
Ottewill, R. & Shaw, J. Studies on the preparation and characterisation of monodisperse polystyrene latices. Colloid Polym. Sci. 218, 34–40 (1967)
Pelton, R. H. & Chibante, P. Preparation of aqueous lattices with n-isopropylacrylamide. Colloids Surf. 20, 247–256 (1986)
Acknowledgements
This work was partially supported by National Science Foundation grants DMR 0706453 and the Keck Foundation. S.S. was supported by the Netherlands Organization for Scientific Research (NWO) through a Rubicon fellowship. W.T.M.I. acknowledges support from the English Speaking Union through a Lindemann Fellowship and Rhodia.
Author Contributions S.S. designed the lock synthesis, synthesized all the colloidal systems, designed and performed the experiments and analysed data. W.T.M.I. designed the experiments, performed field manipulation experiments, analysed data and theoretically modelled the system. D.J.P. and P.M.C. conceived of the depletion-induced colloidal lock-and-key interaction, initiated and supervised the research. The manuscript was written by S.S., W.T.M.I. and D.J.P.
Author information
Authors and Affiliations
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
This file contains Supplementary Data including Figure 1 and legend, Supplementary References and Supplementary Figures S1 and legend. (PDF 878 kb)
Supplementary Movie 1
This movie file shows the sequential self-assembly of a flexible colloidal molecule via our novel recognition mechanism. A lock-key complex forms only when a matching key particle (here a 1.57μm silica sphere) docks at the lock cavity site (green arrow). All other configurations result in repulsive interactions (red arrow). A key particle can accommodate more than one lock. The movie was acquired at 1 fr/s and it is displayed at 8.7 fr/s. (MOV 2937 kb)
Supplementary Movie 2
This movie file shows the simultaneous unbinding of two lock-key complexes controlled by temperature. When the temperature is raised the depletant shrinks (pNIPAM microgel particles not visible in the movie) and the attractive depletion potential falls below that required for binding. As a result, the locks release their bound keys. The movie was acquired at 10.7 fr/s and it is displayed at 12.8 fr/s. (MOV 2210 kb)
Supplementary Movie 3
This movie file shows self-assembled colloidal molecules with flexible bonds between their constituent particles. The flexibility is given by ball-and-socket joints held together by the depletion force. Movies were acquired at 1 fr/s and they are displayed at 10 fr/s (MOV 395 kb)
Supplementary Movie 4
This movie file shows self-assembled colloidal molecules with flexible bonds between their constituent particles. The flexibility is given by ball-and-socket joints held together by the depletion force. Movies were acquired at 1 fr/s and they are displayed at 10 fr/s (MOV 1062 kb)
Supplementary Movie 5
This movie file shows a freely diffusing flexible colloidal polymer consisting of interconnected locks. The movie was acquired at 10.7 fr/s and it is displayed at 23.5 fr/s. (MOV 1680 kb)
Supplementary Movie 6
This movie file is showing a typical, randomly selected "full field of view" of our sample containing ~60× lock-key assemblies. (MOV 4955 kb)
Rights and permissions
About this article
Cite this article
Sacanna, S., Irvine, W., Chaikin, P. et al. Lock and key colloids. Nature 464, 575–578 (2010). https://doi.org/10.1038/nature08906
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature08906
This article is cited by
-
Programming structural and magnetic anisotropy for tailored interaction and control of soft microrobots
Communications Engineering (2024)
-
On the Global Minimum of the Classical Potential Energy for Clusters Bound by Many-Body Forces
Journal of Statistical Physics (2024)
-
Visualizing defect dynamics by assembling the colloidal graphene lattice
Nature Communications (2023)
-
Janus particles with tunable patch symmetry and their assembly into chiral colloidal clusters
Nature Communications (2023)
-
Colloidal robotics
Nature Materials (2023)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.