A new strategy for the synthesis of a mushroom-like aggregate, based on repeated sequences of a 3D gold nanoparticle–conducting polymer–gold nanoparticle arrangement, by a single-step process at the organic/water interface has been described.

We focused on changes in the electrical property of the open bridge-structured gold nanoparticles array consisting of 46-nm parent and 12-nm son gold nanoparticles by hybridization and applied it for a simple electrical DNA detection. Since a target DNA of a 24-mer oligonucleotide was added to the probe DNA modified 12-nm Au nanoparticles, which was arranged on the gap between the 46-nm Au particles, the response was read by an electrical readout system. Even in a simple measuring method, we obtained a rapid response to the cDNA with a high S/N ratio of 30 over a wide concentration range and a detection limit of 5.0 fmol. Moreover, the array discriminated 1-base mismatches, regardless of their location in the DNA sequence, which enabled us to detect single-nucleotide polymorphism, which is one of the important diagnoses, without any polymerase chain reaction amplification, sophisticated instrumentation, or fluorescent labeling through an easy-to-handle electrical readout system.

Self-assembling particles were prepared by a new synthetic strategy for a raspberry-like aggregate, based on three-dimensional particle–aniline oligomer–particle repeated sequences; this one-step process, without the need for extra control, organic solvents, or ligand exchange, could further help in the realization of nanoscale electronics and molecular devices.

A new strategy for the synthesis of a mushroom-like aggregate, based on repeated sequences of a 3D gold nanoparticle–conducting polymer–gold nanoparticle arrangement, by a single-step process at the organic/water interface has been described.