Chirality transfer induced circularly polarized luminescence of achiral dye molecules by plasmonic nanohelicoid

Abstract

Optical materials with circularly polarized luminescence (CPL) features have attracted a growing interest due to their crucial role in biological sensing, display, spintronics, information storage, and so forth. However, CPL emissions in hybrid nanoparticle systems, in particular, chirality transfer induced CPL from chiral plasmonic nanoparticles, have rarely been explored due to a lack of effective bottom-up synthesis method. Herein, we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid (GNH) to excite the CPL of achiral Rhodamine 6G (R6G). The fabricated GNH@R6G-SiO₂ shows obvious CPL signals with ∣g_lum∣ up to 0.014. Compared with the single GNH, the photoluminescence (PL) dissymmetry factor of the single GNH@R6G-SiO₂ is similar, but with 25 folds higher PL intensities under different circular polarization. Our research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials, but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures, thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing, especially some intracellular chirality related detection.