Functional and Universal Surface Anchors Based on N-Heterocyclic Carbenes

Technology      

One of the long-standing problems in surface chemistry is the lack of a universal anchor group that offers strong and well-defined surface binding, better electronic coupling with the surface, and addressable functionality. Known for their strong binding to a variety of metals and metalloids, N-heterocyclic carbenes (NHCs) were chosen as candidate surface-coating molecules. The current technology creates novel addressable NHC-based anchors, confirming and defining their binding and electronic coupling to gold, while demonstrating their aptitude for tandem functionalization of gold surfaces. Most current methods for modifying gold surfaces use thiols as linking molecules. Thiols bind the gold surface and then serve as an anchor for adding functional groups that have useful properties. However, this approach has two major drawbacks: 1) the gold-thiol bonds are weak, and can be disrupted by heat or chemical oxidation; and 2) they are sometimes poor electrical conductors, limiting their use for electronics applications. This technology is a method to functionalize surfaces using NHC molecules as anchors.  The NHC bonds are better electrical conductors, so this technology is well-suited for microelectronics and molecular electronics. In addition to modifying gold surfaces, this technology can be extended to work on other types of surfaces, making it a uniquely versatile method with a broad range of applications. Because the NHCs can attach functional groups, potential applications are extended to biomedical and electronic uses, such as biosensors, nanoparticles for drug delivery and medical imaging, biomedical and industrial coatings, and semiconductor manufacturing.  

Problem Addressed

This technology introduces a new surface coating system, where N-heterocyclic carbenes (NHCs) are attached to surfaces, forming anchors for further surface functionalization, while ensuring durable attachment and conductivity.  

Advantages 

• NHC bonds at the surface are strong and offer durable materials
• Coatings are more conductive, allowing microelectronics applications
• NHCs can serve as anchors to chemically or electrically modify the surface
• NHCs can bind to a variety of surfaces including gold, silver, silicon, and quantum dots  

Publications

PEGylated N-Heterocyclic Carbene Anchors Designed To Stabilize Gold Nanoparticles in Biologically Relevant Media. Journal of the American Chemical Society 137, no. 8 (2015): 2569-2576.

Addressable Carbene Anchors for Gold Surfaces. Journal of the American Chemical Society 135, no. 18 (May 13, 2013): 6834-6837.