# Linker-mediated phase behavior of DNA-coated colloids

## TL;DR

This paper introduces a new approach to programmable self-assembly of DNA-coated colloids using linker oligonucleotides, revealing complex phase behavior and enabling precise control over colloidal interactions.

## Contribution

It presents a novel linker-mediated paradigm for DNA colloid assembly, with a comprehensive phase diagram and a predictive theory matching experimental results.

## Key findings

- Re-entrant melting transition observed with increasing linker concentration
- Multiple linker species can be combined for complex interactions
- Theoretical model accurately predicts phase behavior without fitting

## Abstract

The possibility of prescribing local interactions between nano- and microscopic components that direct them to assemble in a predictable fashion is a central goal of nanotechnology research. In this article we advance a new paradigm in which self-assembly of DNA-functionalized colloidal particles is programmed using linker oligonucleotides dispersed in solution. We find a phase diagram that is surprisingly rich compared to phase diagrams typical of other DNA-functionalized colloidal particles that interact by direct hybridization, including a re-entrant melting transition upon increasing linker concentration, and show that multiple linker species can be combined together to prescribe many interactions simultaneously. A new theory predicts the observed phase behavior quantitatively without any fitting parameters. Taken together, these experiments and model lay the groundwork for future research in programmable self-assembly, enabling the possibility of programming the hundreds of specific interactions needed to assemble fully-addressable, mesoscopic structures, while also expanding our fundamental understanding of the unique phase behavior possible in colloidal suspensions.