January 14, 2021
Journal Article

Peptoid-Directed Assembly of CdSe Nanoparticles

Abstract

The high information content of proteins drives their hierarchical assembly and complex function, including the organization of inorganic nanomaterials. Peptoids offer an organic scaffold very similar to proteins, but with a wider solubility range and easily tunable side chains and functional groups to create a variety of self-assembling architectures with atomic precision. If we could harness this paradigm and understand the factors that govern how they direct nucleation and assembly of inorganic materials to design order within such materials, new dimensions of function and fundamental science would emerge. In this work, peptoid tubes and sheets were explored as platforms to assemble colloidal quantum dots (QDs) and clusters. We have successfully synthesized CdSe QDs with difunctionalized capping ligands containing both carboxylic acid and thiol groups and mixed them with maleimide containing peptoids, to create an assembly of the QDs on the peptoid surface via a covalent linkage. This conjugation was seen to be successful with peptoid tubes, sheets and CdSe QDs and clusters. The particles were seen to have a high preference for the peptoid surface but non-specific interactions with carboxylic acid groups on the peptoids limited control over QD density via the maleimide conjugation. Replacing the carboxylic acid groups with methoxy ethers allowed for control over QD density as a function of maleimide concentration. 1H NMR analysis demonstrated that binding of QDs to peptoids involved a subset of surface ligands bound via the carboxylate functional group, allowing sulfur to bind via covalent linkage to the maleimide. Overall, we have shown the compatibility and control of CdSe-peptoid interactions via a covalent linkage with varying peptoid structures and CdSe particles to create complex hybrid structures.

Revised: February 15, 2021 | Published: January 14, 2021

Citation

Monahan M.C., B. Cai, T. Jian, S. Zhang, G. Zhu, C. Chen, and J.J. De Yoreo, et al. 2021. "Peptoid-Directed Assembly of CdSe Nanoparticles." Nanoscale 13, no. 2:1273-1282. PNNL-SA-158881. doi:10.1039/D0NR07509D