Click-Chemistry-Enabled Functionalization of Cellulose Nanocrystals with Single-Stranded DNA for Directed Assembly

Controlling the self-assembly of cellulose nanocrystals (CNCs) requires precise control over their surface chemistry for the directed assembly of advanced nanocomposites with tailored mechanical, thermal, and optical properties. In this work, in contrast to traditional chemistries, we conducted highly selective click-chemistry functionalization of cellulose nanocrystals with complementary DNA strands via a three-step hybridization-guided process. By grafting terminally functionalized oligonucleotides through copper-free click chemistry, we successfully facilitated the assembly of brushlike DNA-modified CNCs into bundled nanostructures with distinct chiral optical dichroism in thin films. The complexation behavior of grafted DNA chains during the evaporation-driven formation of ultrathin films demonstrates the potential for mediating chiral interactions between the DNA-branched nanocrystals and their assembly into chiral bundles. Furthermore, we discuss the future directions and challenges that include new avenues for the development of functional, responsive, and bioderived nanostructures capable of dynamic reconfiguration via selective complexation, further surface modification strategies, mitigating diverse CNC aggregation, and exploring environmental conditions for the CNC-DNA assembly.