Monolayers with N-hydroxysuccinimide (NHS) ester terminal groups are widely used to couple amine-containing biomolecules such as proteins and peptides to surfaces for many types of bioanalytical platforms.  Though this pathway simplifies tethering of biomolecules to surfaces via amide linkages, hydrolysis of the NHS group competes with amidization.  This presentation discusses an investigation using succinimidyl ester-terminated monolayers on gold formed from disulfides of various chain lengths.  Hydrolysis reactions were performed in borate buffer, while aminolysis reactions used a model amine molecule at various concentrations (50 to 500 mM) and pH (8.5 to 10.5).  Structure and reactivity of these adlayers were analyzed using infrared reflection spectroscopy, X-ray photoelectron spectroscopy, electrochemical reductive desorption, and contact angle measurements.  Results show hydrolysis occurs more rapidly for shorter chain length systems, but aminolysis overcomes hydrolysis at higher amine concentrations and pH.  The importance of applying this form of coupling chemistry to protein immobilization is discussed.?

Competing reactions on monolayers: Formation of amide linkages via succinimidyl ester chemistry

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.