Tunable oligo-histidine self-assembled monolayer junction and charge transport by a pH modulated assembly. Issue 47 (20th November 2019)

• Record Type: Journal Article
• Authors: Li, Baili; Tian, Lixian; He, Xuehao; Ji, Xuan; Khalid, Hira; Yue, Chong; Liu, Qinggang; Yu, Xi; Lei, Shengbin; Hu, Wenping
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 47(2019)
• Page Start: 26058
• Page End: 26065
• Publication Date: 2019-11-20
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp04695j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Tunable charge transport of hepta-histidine self-assembled monolayer junction via pH modulated assembly. Abstract : Histidine works as an important mediator in the charge transport process through proteins via its conjugate side group. It can also stabilize a peptide's secondary structure through hydrogen bonding of the imidazole group. In this study, the conformation of the self-assembled monolayer (SAM) and the charge transport of the tailor-made oligopeptide hepta-histidine derivative (7-His) were modulated through the pH control of the assembly environment. Histidine is found to be an efficient tunneling mediator in monolayer junctions with an attenuation factor of β = ∼0.5 Å −1 . Successful theoretical model fitting indicates a linear increase in the number of tunneling sites as the 7-His SAM thickness increases, following the deprotonation of histidine. Combined with the ultraviolet photoelectron spectroscopy (UPS) measurements, a modulable charge transport pathway through 7-His with imidazole groups of histidine as tunneling foot stones is revealed. Histidine therefore possesses a large potential for modulable functional (bio)electronic devices.