DNA–Gold Nanorod Composite Films as Anisotropic Light-Scattering Layers

Controlling light scattering in thin films is a key challenge for advanced optical applications, including displays, sensors, and photonic devices. In this study, we demonstrate that DNA–gold nanorod (GNR) composite films can function as an effective anisotropic scattering layer through controlled structural alignment.

The DNA matrix, which exhibits lyotropic liquid crystalline behavior, enabled long-range molecular alignment via mechanical shearing. This alignment induced periodic topological undulations and anisotropic microstructures within the film, contributing to directional light scattering. GNRs are co-aligned with the DNA matrix embedded gold nanorods induce scattering, leading to increased haze.

By combining these two mechanisms—(i) topological undulation-induced scattering from the aligned DNA structure and (ii) particle-based plasmonic scattering from anisotropically oriented GNRs—we achieve tunable and polarization-dependent light scattering behavior. The resulting composite film exhibits enhanced haze and directional optical response, which can be modulated by controlling the shearing conditions and nanorod alignment.

This work suggests that DNA-based liquid crystalline systems provide a versatile platform for designing bio-derived, solution-processable optical scattering layers, extending their applications beyond conventional biomaterials toward functional photonic and optoelectronic devices.