Specific interaction of DNA-functionalized polymer colloids

As a chemically based assembly system, DNA is a key player for use in the reversible and specific interactions of an advanced material. In this approach, we work with a one-component system where a number of DNA single strands are grafted on the surface of micro-sized particles. The interactions between the DNA-functionalized particles are controlled by the addition of DNA linker in solution, which has complementary sequences with the DNA strands grafted on the particles. The hydrogen bonding based on Watson-Crick pairing is the driving force to form double stranded DNA. Several techniques have been used to characterize this system; for example, optical microscopy, AFM, DLS and flow cytometry. The two DNA strands reversibly separate (denature) above a characteristic melting temperature of DNA's base pair sequences. The melting temperature of DNA in the study is in good agreement with that of calculation based on the thermodynamic point of view.