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Abstract Surface functionalization and colloidal stability are pivotal for numerous applications of gold nanoparticles (Au‐NPs). Over the past decade, N‐heterocyclic carbenes (NHCs) have emerged as promising ligands for stabilizing Au‐NPs owing to their ease of synthesis, structural diversity, and strong metal‐ligand bonds. Here, we introduce new Au(I)–NHCcopolymer scaffolds as precursors to multidentate NHC‐protected Au‐NPs. Ring‐opening metathesis copolymerization of a norbornene‐appended Au(I)−NHC complex with another functionalized norbornene comonomer provides NHC–Au(I) copolymers with modular compositions and structures. Upon reduction, these copolymers yield multidentate polyNHC‐coated Au‐NPs with varied properties and corona functionalities dictated by the secondary monomer. These nanoparticles exhibit excellent size homogeneity and stability against aggregation in various buffers, cell culture media, and under exposure to electrolytes, oxidants, and exogenous thiols over extended periods. Moreover, we demonstrate post‐synthetic surface functionalization reactions of polyNHC−Au‐NPs while maintaining colloidal stability, highlighting their robustness and potential for applications such as bioconjugation. Overall, these findings underscore the potential of ROMP‐derived NHC‐containing copolymers as highly tunable and versatile multidentate ligands that may be suitable for other inorganic colloids and flat surfaces.
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This content will become publicly available on June 22, 2027
Enhancing Interfacial Charge Transport in Gold Nanoparticle@Polyaniline Hybrids via N ‐Heterocyclic Carbene Linkers
ABSTRACT N‐Heterocyclic carbenes (NHCs) have emerged as a unique class of ligands for gold nanoparticles (Au NPs), combining strong metal binding with intrinsic electronic conductivity. Yet over the past decade, studies on Au NP@NHC systems have primarily focused on their stability, while the conductivity of NHCs has remained largely unexplored due to synthesis challenges. Here, we present a synthetic strategy that addresses this gap by employing amino‐functionalized NHC‐Au complexes with in situ oxidative polymerization of polyaniline (PANI) to yield electronically coupled Au NP@NHC‐PANI hybrids in aqueous media. This strategy enables both a controlled PANI shell growth and introduction of an electronically active NHC interlayer. Single‐particle scattering spectroscopy reveals that NHCs improve the interfacial electronic coupling as evidenced by pronounced plasmonic linewidth broadening. Conductivity measurements further confirm that NHCs enhance charge transport: conductive atomic force microscopy (C‐AFM) shows an increase in contact current from 14.6 to 99.4 pA under a 300‐mV bias, while lateral four‐probe conductance increases from 0.17 to 3.5 nS. These results provide the first direct experimental evidence of the conductive role of NHCs in hybrid NP‐polymer systems, establishing a new interface‐engineering strategy for the rational design of electronically delocalized nanostructures and their applications in nanoelectronics.
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- Award ID(s):
- 2404220
- PAR ID:
- 10707628
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 138
- Issue:
- 26
- ISSN:
- 0044-8249
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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