Programming the kinetics and extent of colloidal disassembly using a DNA trigger

We present experimental studies of the effects of DNA sequence length and concentration on the kinetics of competitive hybridization events in colloidal suspensions. We quantify both the number of displaced soluble target strands and the extent of disassembly of DNA-linked colloidal micelles or colloidal satellites using flow cytometry. The kinetics of competitive displacement of soluble targets are on the order of minutes whereas disassembly of the colloidal micelles requires several hours and even days. By fitting the data to a first-order equation, we found that the observed replacement rate for the soluble target system depends on target base length differences as well as the concentration of the competitive strands. Our studies illustrate that DNA can be employed as a programmable, isothermal disassembly tool for DNA-linked colloidal particles.