Electron Transfer Studies on Self-Assembled Monolayers of Helical Ferrocenoyl-Oligoproline-Cystamine Bound to Gold

Characteristic differences in the X-ray photoelectron spectrum between B-DNA and M-DNA monolayers on gold

“…The DNA was manually spread to cover the entire gold surface area. The electrodes were placed in a sealed container and kept in a humidifier for 5 days in order to prevent evaporation of the samples [9,23]. After the five day incubation, the wafers were washed thoroughly with buffer in order to remove nonspecifically bound DNA and dried with Argon gas before measurements were taken [24].…”

Distance dependence of long‐range electron transfer through helical peptides

“…Especially, electron transfer through helices has attracted much attention because it is believed that α-helical segments play an essential role in mediating an electron and determining its direction in biological systems [6]. To study the nature of electron transfer, radiolysis [7,8] and photoinduced electron-transfer [9] studies in solution (donor-peptide-acceptor), electrochemical studies on self-assembled monolayer (SAM) systems (donor-peptide-metal) [10][11][12][13][14][15], and recently, single molecule measurements by scanning probe microscopy (metal-peptide-metal) [16][17][18], have been conducted intensively. Most of the researchers agree that a helical peptide is a good electron mediator and enables electron transfer over a long distance.…”

“…We thus suggested that a hopping mechanism with amide groups as hopping sites was responsible for this long-range electron transfer. Kraatz and co-workers studied a similar monolayer system with Pro-based peptides carrying a ferrocene moiety at the terminal, and they observed a very weak distance dependence that could be attributed to hopping [12,13]. Recently, however, they have emphasized the importance of molecular dynamics whether the electron transfer is governed by tunneling or hopping [14].…”

Hexachloroiridate(IV) as a redox probe for the electrochemical discrimination of B-DNA and M-DNA monolayers on gold

“…The DNA was deposited onto the freshly prepared gold electrode and the electrodes were incubated for five days in a sealed humidifier in order to prevent evaporation of the samples [17,24]. The electrodes were rinsed thoroughly with buffer solution in order to remove nonspecifically bound DNA and mounted into an electrochemical cell [25].…”