Fluorescence Filter Nanoarchitectonics with Polydiacetylene‐Based Supramolecular Chiral Gel for Generating Tunable Circularly Polarized Luminescence

Abstract Circularly polarized luminescence (CPL) can be generated from chiral luminescent materials. It can also be achieved from achiral emissive dyes by selectively filtering their fluorescence with chiroptical active materials. In this work, a novel polydiacetylene‐based supramolecular chiral gel is fabricated as a handedness‐selective fluorescence filter for generating CPL. The gelator consists of a diacetylene alkyl chain and a chiral histidine (His) head group (HisDA). It can self‐assemble into nanoribbon and turn into the blue phase, purple phase and red phase polydiacetylene‐His (HisPDA) upon photopolymerization. The resulting L/D‐HisPDA gels show variable circular dichroism (CD) with the change in color. Furthermore, multiple CPL signals are achieved after fluorescence excited with achiral dyes D1–D3 passing through HisPDA gel. The intensity of CPL increases gradually in both D1 and D3 dye systems along with the change of the HisPDA gel from blue phase to red phase, while the CPL signal is inverted for the D2 dye system. The handedness of the CPL signal is opposite to the CD signal of HisPDA gel in all the cases, demonstrating that CPL is originated through a handedness‐selective fluorescence adsorption mechanism. This study offers a new strategy for obtaining tunable CPL via adjustable chiral fluorescence filters.