초록 |
Over the past decades, DNA complementary binding have led great advances in programmable crystallization of gold (Au) colloids through their exquisite ability over the 3D lattice engineering. However, their successes have been limited in relatively small (< 30 nm) Au nanospheres (NSs), because the larger Au NPs are more liable to kinetic trapping. Such limitation has restricted the applications of the assembled plasmonic crystal in sub-wavelength-scaled optics. In this work, we address this challenge by using DNA base-pair stacking rather than complementary binding for the crystallization of large Au NSs. Benefitting from the milder interaction strength of base pair-stacking than complementary counterpart, 75 nm Au NSs were crystallized into FCC lattice with the large area up to 1400 μm2. A metallodielectric stopband was experimentally investigated and show great deal of agreement with theoretical prediction, reflecting high structural integrity of the assembled crystal. |