Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

単分子L-システイン修飾金電極を用いた電気化学反応による選択的分子反応制御

本田 充紀   ; 馬場 祐治  ; 関口 哲弘  ; 下山 巖   ; 平尾 法恵

Honda, Mitsunori; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules.