(684e) Probing the Interactions and Dynamics of DNA-Functionalized Colloids with Scanning-Line Optical Tweezers | AIChE

(684e) Probing the Interactions and Dynamics of DNA-Functionalized Colloids with Scanning-Line Optical Tweezers


Rogers, W. B. - Presenter, University of Pennsylvania
Crocker, J. - Presenter, University of Pennsylvania

DNA hybridization is an ideal tool to direct ?bottom-up? assembly of complex materials and has recently been used to assemble quantum dots1, polymer microspheres2 and other materials made exclusively of DNA3. Even with the significant interest in DNA as a self-assembly platform, very few groups report successful formation of self-assembled, crystalline materials4-6. Previous work from our group suggests that success in making crystalline assemblies may have been frustrated by a combination of slow binding dynamics and a narrow temperature window for nucleation and crystal growth7. To address these issues, we use a scanning-line optical tweezers instrument to measure DNA-induced interactions between colloidal microspheres and then model the pair potentials using well-known concepts in statistical mechanics and chemistry. By measuring and modeling the pair interaction energies of DNA-functionalized particles as a function of temperature and separation distance, we are able to develop a simple toolbox of DNA architectures that can be used to independently tune the dynamics and binding energies in a rational way.

1. Mirkin, C.A., Letsinger, R.L., Mucic, R.C., & Storhoff, J.J., A DNA-based method for rationally assembling nanoparticles into macroscopic materials. Nature 382 (6592), 607-609 (1996). 2. Soto, C.M., Srinivasan, A., & Ratna, B.R., Controlled assembly of mesoscale structures using DNA as molecular bridges. Journal of the American Chemical Society 124 (29), 8508-8509 (2002). 3. Rothemund, P.W.K., Folding DNA to create nanoscale shapes and patterns. Nature 440 (7082), 297-302 (2006). 4. Biancaniello, P.L., Kim, A.J., & Crocker, J.C., Colloidal interactions and self-assembly using DNA hybridization. Phys. Rev. Lett. 94 (5), 058302 (2005). 5. Nykypanchuk, D., Maye, M.M., van der Lelie, D., & Gang, O., DNA-guided crystallization of colloidal nanoparticles. Nature 451 (7178), 549-552 (2008). 6. Park, S.Y. et al., DNA-programmable nanoparticle crystallization. Nature 451 (7178), 553-556 (2008). 7. Kim, A.J., Scarlett, R., Biancaniello, P.L., Sinno, T., & Crocker, J.C., Probing interfacial equilibration in microsphere crystals formed by DNA-directed assembly. Nature Mater. 8 (1), 52-55 (2009).