A simple method to reprogram the binding specificity of DNA-coated colloids that crystallize

DNA-coated particles are versatile building-blocks for self-assembly, but difficult, costly, and time-consuming to produce in a way that is compatible with equilibrium self-assembly. For each experiment or application that requires a different DNA sequence on the particle, the DNA grafting process needs to be repeated, standing in the way of the widespread use of DNA-coated colloids in research and commercial applications. Here, we introduce a method to convert generic DNA-coated colloids into building blocks with user-specified DNA sequences by appending new DNA domains onto the DNA grafted onto the colloid. The reaction we introduce is easy and fast, reaching $100\%$ conversion in 1h. We show that the assembly properties of particles produced via our conversion method are indistinguishable from those produced via click chemistry directly. Moreover, we show that one generic type of particle can be converted into a variety of assembly building blocks with differing specificity by appending different DNA sequences onto them. We expect that our approach will greatly improve access to DNA-coated particles that can crystallize and pave the way to their commercial application.