  DNA-coated colloids can crystallize into a multitude of lattices, ranging
from face-centered cubic to diamond and thereby contribute to our understanding
of crystallization and open avenues to producing structures with useful
photonic properties. Despite the broad potential design space of DNA-coated
colloids, the design cycle for synthesizing DNA-coated particles is slow:
preparing a particle with a new type of DNA sequence takes more than one day
and requires custom-made and chemically modified DNA that typically takes the
supplier over a month to synthesize. Here, we introduce a method to generate
particles with custom sequences from a single feed stock in under an hour at
ambient conditions. Our method appends new DNA domains onto the DNA grafted to
colloidal particles based on a template that takes the supplier less than a
week to produce. The resultant particles crystallize as readily and at the same
temperature as those produced via direct chemical synthesis. Moreover, we show
that particles coated with a single sequence can be converted into a variety of
building blocks with differing specificities by appending different DNA
sequences to them. This approach to DNA-coated particle preparation will make
it practical to identify optimal and complex particle sequence designs and to
expand the use of DNA-coated colloids to a much broader range of investigators
and commercial entities.
