DNA and DNAzyme-mediated 2D colloidal assembly.
DNA-mediated interactions present a significant opportunity for controlling colloidal self-assembly. Using microcontact printing to achieve spatial control of DNA-surface patterning and DNA-functionalized polystyrene colloids, we report that DNA hybridization can be utilized for sequence-specific reversible self-assembly of well-ordered 2D colloidal arrays. Two essential indicators of DNA-hybridization mediated assembly were confirmed: thermal reversibility and sequence specificity. The arrays melted at 50 degrees C and reassembled when introduced to fresh colloid suspension, and sequence specificity with <1% nonspecific binding was confirmed using fluorescent polystyrene colloids. The real-time assembly of the colloids onto the periodically patterned substrate was monitored by simple laser diffraction to obtain assembly kinetics. Maximum surface coverage of DNA-mediated assembly was determined to be 0.593 for DNA-functionalized 100 nm polystyrene colloids, and 90% of the assembly was complete after 6.25 h of hybridization in 50 mM NaCl Tris buffer. We also demonstrate that DNAzymes, catalytic DNA molecules, can be incorporated into the design, and in the presence of 10 microM Pb(2+), the hybridization-induced array assembly can be disrupted via DNAzyme activity.
Beckman Institute, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, USA.
Margaret H S
MH
Shyr
Daryl P
DP
Wernette
Pierre
P
Wiltzius
Yi
Y
Lu
Paul V
PV
Braun
D003102:Colloids / Q000737:chemistry*; D004247:DNA; D021881:DNA, Catalytic; D007700:Kinetics; D007834:Lasers; D009693:Nucleic Acid Hybridization; D011137:Polystyrenes
D003102:Colloids; D021881:DNA, Catalytic; D011137:Polystyrenes; D004247:DNA