Terminal alkynes as an ink or background SAM in replacement lithography: adventitious versus directed replacement.

Self-assembled monolayers (SAMs) comprised from n-alkanethiols and terminal alkynes were subjected to solutions containing ferrocene-terminated thiol, thioacetate, and terminal alkyne. The rate and extent of chemical exchange were monitored by scanning tunneling microscopy (STM). In several cases, a rate constant for exchange could be obtained by fitting to a model for exchange.

Reversible addition-fragmentation chain transfer polymerization in DNA biosensing.

Reversible addition-fragmentation chain transfer polymerization is employed here to allow detector-free visualization of specific DNA sequences for which dynamic polymer growth is used in signal amplification. In particular, surface-initiated polymer growth was regulated by the immobilization of chain transfer agents on the Au surface where DNA hybridization occurred. A linear polymer growth was observed as a function of the reaction time, characteristic of "living" polymer reactions.