Selective decomposition of nucleic acids by laser irradiation on probe-tethered gold nanoparticles in solution.

We have developed a new method for selective decomposition of nucleic acids. The method utilizes a high temperature and pressure region (HTP region, hereafter) around a gold nanoparticle, which was generated when the gold nanoparticle was irradiated with a pulsed laser in aqueous solution. A probe DNA molecule whose sequence was complementary to a part of a target DNA molecule was bound to the gold nanoparticle surface. In a solution containing both the target and non-target DNA molecules, the gold nanoparticle selectively attached to the target DNA through hybridization of the probe DNA. When the gold nanoparticle was excited by a pulsed laser, the HTP region was generated in the close vicinity of the gold nanoparticle and then the target DNA molecules inside of this region were decomposed. The non-target DNA molecules having no part complementary to the probe DNA were scarcely decomposed by laser irradiation. When the gold nanoparticle was excited by an intense laser, the non-target DNA molecules were also decomposed, because some of them were located inside the inflated HTP region. We discussed the mechanism of the decomposition of the DNA molecules by the HTP region.