DNA linked nanoparticles are applied as a sensor for single-stranded DNA detection. The detection is based on nanocluster dimer disassembly triggered by the binding of target nucleic acid strands. Target detection and disassembly kinetics are followed in real-time using dynamic light scattering. The observed disassembly process is in agreement with a two-step kinetic model. The DNA sensing is found to be selective down to the level of a single base mismatch, even in the presence of a high concentration of interference DNA. The method further provides label-free detection of DNA in minutes and demonstrates the use of this new class of nanoclusters as a powerful platform for nucleic acid detection.