12 research outputs found
High-Transconductance Graphene Solution-Gated Field Effect Transistors
In this work, we report on the electronic properties of solution-gated field
effect transistors (SGFETs) fabricated using large-area graphene. Devices
prepared both with epitaxially grown graphene on SiC as well as with chemical
vapor deposition grown graphene on Cu exhibit high transconductances, which are
a consequence of the high mobility of charge carriers in graphene and the large
capacitance at the graphene/water interface. The performance of graphene
SGFETs, in terms of gate sensitivity, is compared to other SGFET technologies
and found to be clearly superior, confirming the potential of graphene SGFETs
for sensing applications in electrolytic environments.Comment: The following article has been submitted to Applied Physics Letters.
After it is published, it will be found at apl.aip.or
Three-Dimensional Bicomponent Supramolecular Nanoporous Self-Assembly on a Hybrid All-Carbon Atomically Flat and Transparent Platform
Molecular
self-assembly is a versatile nanofabrication technique
with atomic precision en route to molecule-based electronic components
and devices. Here, we demonstrate a three-dimensional, bicomponent
supramolecular network architecture on an all-carbon sp<sup>2</sup>âsp<sup>3</sup> transparent platform. The substrate consists
of hydrogenated diamond decorated with a monolayer graphene sheet.
The pertaining bilayer assembly of a melamineânaphthalenetetracarboxylic
diimide supramolecular network exhibiting a nanoporous honeycomb structure
is explored via scanning tunneling microscopy initially at the solution-highly
oriented pyrolytic graphite interface. On both graphene-terminated
copper and an atomically flat graphene/diamond hybrid substrate, an
assembly protocol is demonstrated yielding similar supramolecular
networks with long-range order. Our results suggest that hybrid platforms,
(supramolecular) chemistry and thermodynamic growth protocols can
be merged for in situ molecular device fabrication
Addressing Single Nitrogen-Vacancy Centers in Diamond with Transparent in-Plane Gate Structures
For many applications of the nitrogen-vacancy
(NV) center in diamond,
the understanding and active control of its charge state is highly
desired. In this work, we demonstrate the reversible manipulation
of the charge state of a single NV center from NV<sup>â</sup> across NV<sup>0</sup> to a nonfluorescent, dark state by using an
all-diamond in-plane gate nanostructure. Applying a voltage to the
in-plane gate structure can influence the energy band bending sufficiently
for charge state conversion of NV centers. These diamond in-plane
structures can function as transparent top gates, enabling the distant
control of the charge state of NV centers tens of micrometers away from the nanostructure
Addressing Single Nitrogen-Vacancy Centers in Diamond with Transparent in-Plane Gate Structures
Experimental and computational framework for a dynamic protein atlas of human cell division.
Essential biological functions, such as mitosis, require tight coordination of hundreds of proteins in space and time. Localization, the timing of interactions and changes in cellular structure are all crucial to ensure the correct assembly, function and regulation of protein complexes(1-4). Imaging of live cells can reveal protein distributions and dynamics but experimental and theoretical challenges have prevented the collection of quantitative data, which are necessary for the formulation of a model of mitosis that comprehensively integrates information and enables the analysis of the dynamic interactions between the molecular parts of the mitotic machinery within changing cellular boundaries. Here we generate a canonical model of the morphological changes during the mitotic progression of human cells on the basis of four-dimensional image data. We use this model to integrate dynamic three-dimensional concentration data of many fluorescently knocked-in mitotic proteins, imaged by fluorescence correlation spectroscopy-calibrated microscopy(5). The approach taken here to generate a dynamic protein atlas of human cell division is generic; it can be applied to systematically map and mine dynamic protein localization networks that drive cell division in different cell types, and can be conceptually transferred to other cellular functions