Co‐Assembly of Biosynthetic Chiral Nematic Adhesive Materials with Dynamic Polarized Luminescence

Abstract There is currently an extensive demand for simple and effective synthetic methods to allow the design and fabrication of robust and flexible chiral materials that can generate strong and switchable circularly polarized luminescence (CPL). Herein, biosynthetic light‐emitting adhesive materials based upon chiral nematic cellulose nanocrystal–polyelectrolyte complexes with universal high adhesion on both hydrophilic and hydrophobic substrates are reported. Strong and dynamic photoluminescence with highly asymmetric and switchable circular polarization is induced by minute rare earth europium doping without compromising adhesive strength and initial iridescent properties. The photoluminescence can be temporarily quenched with highly volatile acetone vapor and liquid followed by fast recovery after drying with full restoration of initial emission. The unique properties of light‐emitting bio‐adhesives with universal adhesion, amplified and dynamic photoluminescence, and large and switchable CPL can be utilized for security optical coding, bio‐optical memory, hidden communication, and biochemical sensing as wearable stickers, prints, and tattoos to directly adhere to human clothes, gadgets, and skin by using adhesive stickers with bright tailored photoluminescence.