DNA linkers surfing on colloids: How surface-mobile DNA linkers affect colloidal self-assembly

DNA linkers surfing on colloids: How surface-mobile DNA linkers affect colloidal self-assembly

Van der Meulen, S.A.J.

Dogterom, M. (promotor)

Applied Sciences

Bionanoscience

2016-02-19

This thesis revolves around exploiting the specificity of DNA interactions to guide the assembly of micro-colloids into higher order structures. The concept of DNA mediated interactions between micro-colloids is a field of study that has ramified from the field on DNA guided self-assembly of nano-colloids. Despite the great potential that the use of DNA could offer for self-assembling micro-colloids, so far the predicted astounding results are still to be accomplished. As compared to the wide variety of self-assembled higher order structures that have been realized with DNA coated nano-colloids, for micron-sized colloids new strategies appear to be needed. Motivated by the high potential of the field and the challenges that are confronted herein, we initiated an experimental project aimed to design and implement a novel strategy aimed to uplift the self-assembly process. This is achieved by both modifying the way the DNA strands are coupled to the particles’ surface and in parallel exploiting sensitive force spectroscopy techniques to elucidate the interaction strengths of the DNA bridges at different conditions. For this purpose, we modified an existing system of micro-colloids coated with DNA in such a way that while the DNA is confined to the surface of the particles, its lateral diffusivity is maintained. The surface mobility is accomplished by surrounding silica micro-particles with a lipid bilayer into which the DNA strands are embedded. This way the lipid bilayer functions as a two dimensional platform in which the DNA strands can ‘float’ like sea beacons that are drifting in water. The size and composition of the silicon oxide micro-particles permit easy visualization by various optical microscopy techniques and facile manipulation with optical tweezers, making them excellent platforms for probing the strength of the DNA-mediated interactions.

colloids

https://doi.org/10.4233/uuid:7edabd84-ca54-455a-82fe-8064226f7c3c

2017-02-19

978-90-8593-247-5

Institutional Repository

doctoral thesis

(c) 2016 Van der Meulen, S.A.J.