Rapid, Reduced-Volume Langmuir Assembly of Nanostructured Surfaces for Inorganic Nanocrystal Assembly and Multivalent Binding

Langmuir-based assembly techniques provide a powerful route for interfacial functionalization, in some cases with nanometer-scale control. In application-driven nanomaterials research, requiring reasonably high throughput and routine functionalization over large areas, it is important to assess whether precise interfacial nanostructure necessitates the level of control afforded by conventional Langmuir troughs, or whether a simplified and more scalable process can reliably produce well-defined nanostructured interfaces. Here, we examine this question in the context of Langmuir–Schaefer transfer onto highly oriented pyrolytic graphite (HOPG). Using striped (lamellar) phases of diacetylene amphiphiles as a model system that generates nanometer-resolution functional patterns, and requires precise molecular ordering to enable topochemical on-surface polymerization, we compare films prepared using a simplified fast Langmuir assembly and heated transfer (FAST-LAM) protocol with those assembled using a conventional Langmuir trough. Across multiple diacetylene building blocks, FAST-LAM produces monolayers with equivalent nanoscale ordering, microscale uniformity, and polymerization behavior, as assessed by atomic force microscopy (nanostructure), electron microscopy (microscale domain structure), and fluorescence measurements (micro-to-macroscopic functional assessment). Together, this hierarchical characterization workflow demonstrates functional equivalence of the streamlined assembly process. We further show rapid preparation of surfaces with ∼1 nm functional patterns that direct assembly of <2 nm diameter gold nanowires, and patterns that induce multivalent binding of proteins. These findings establish a foundation for rapid, high-resolution surface functionalization for applications including inorganic nanostructure assembly and sensing.