Covalent Functionalization of Dipole‐Modulating Molecules on Trilayer Graphene: An Avenue for Graphene‐Interfaced Molecular Machines

Abstract

The molecular dipole moment plays a significant role in governing important phenomena like molecular interactions, molecular configuration, and charge transfer, which are important in several electronic, electrochemical, and optoelectronic systems. Here, the effect of the change in the dipole moment of a tethered molecule on the carrier properties of (functionalized) trilayer graphene--a stack of three layers of sp(2)-hybridized carbon atoms--is demonstrated. It is shown that, due to the high carrier confinement and large quantum capacitance, the trans-to-cis isomerisation of 'covalently attached' azobenzene molecules, with a change in dipole moment of 3D, leads to the generation of a high effective gating voltage. Consequently, 6 units of holes are produced per azobenzene molecule (hole density increases by 440 000 holes μm(-2)). Based on Raman and X-ray photoelectron spectroscopy data, a model is outlined for outer-layer, azobenzene-functionalized trilayer graphene with current modulation in the inner sp(2) matrix. Here, 0.097 V are applied by the isomerisation of the functionalized azobenzene. Further, the large measured quantum capacitance of 72.5 μF cm(-2) justifies the large Dirac point in the heavily doped system. The mechanism defining the effect of dipole modulation of covalently tethered molecules on graphene will enable future sensors and molecular-machine interfaces with graphene.

The effect of ‘Candidatus Liberibacter asiaticus’ infection on the proteomic profiles and nutritional status of pre-symptomatic and symptomatic grapefruit (Citrus paradisi) plants

“…Interestingly, the concentration of K was increased by 12% ( P  > 0.05) and 21% ( P  < 0.05) in IP and IS plants, respectively, compared to their corresponding control plants (Figure  5). Nutrient-disease interactions in plants have been well documented [19]. Low Ca in plant tissues was associated with susceptibility to macerating diseases caused by Erwinia carotovora, Fusarium solani, Pythium myriotylum, Rhizoctonia solani, Sclerotinia minor, and Sclerotium rolfsii [19].…”

“…Furthermore, disease symptoms frequently reflect the altered nutritional status of plants and nutrient-disease interactions are well documented in plant systems [19]. A malfunctioning or blocked vascular system such as that implicated in HLB-disease development [4,13] can induce a systemic or localized nutrient sufficiency or deficiency.…”

“…A malfunctioning or blocked vascular system such as that implicated in HLB-disease development [4,13] can induce a systemic or localized nutrient sufficiency or deficiency. Physiological symptoms of HLB is suggested to resemble that of Zn-deficiency [20] and the productive life of diseased plants, including HLB-affected plants, has been shown to be extendable by fertilizer application [19,21]. Nutrient homeostasis forms part of a delicately balanced interdependent system with plant gene regulation; however, there is limited information on the relationships between the nutritional status and protein expression profiles of citrus plants during HLB development.…”

Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

“…X-ray photoelectron spectroscopy (XPS): Sample preparation and data collection are similarly described in a previous paper [71]. Data was recorded with a Perkin-Elmer PHI 5400 electron spectrometer using acrochromatic Al Kα radiation (1486.6 eV).…”

Bonding, charge rearrangement and interface dipoles of benzene, graphene, and PAH molecules on Au(1 1 1) and Cu(1 1 1)

“…Graphene-like nano-templates such as graphene-like nano-ribbons or even PAH molecules are believed to possess unprecedented technological potential for the development of molecular low-dimensional devicessystems of paramount importance for the emerging graphene-based electronics. The technological applications might range from solar cells, gas sensors, and organic semiconductor devices to even molecular machines [16]. This could be achieved, for instance, by depositing low-dimensional graphene-like nano-templates on transition metal surfaces.…”