Sensing the electrical activity of single ion channels with top-down silicon nanoribbons.
Ontology highlight
ABSTRACT:
SUBMITTER: Zhou W
PROVIDER: S-EPMC6390970 | biostudies-literature | 2018 Jun
REPOSITORIES: biostudies-literature
Publications
Sensing the electrical activity of single ion channels with top-down silicon nanoribbons.
Zhou Weiwei W Mu Luye L Li Jinfeng J Reed Mark M Burke Peter J PJ
Nano futures 20180612 2
Using top-down fabricated silicon nanoribbons, we measure the opening and closing of ion channels alamethicin and gramicidin A. A capacitive model of the system is proposed to demonstrate that the geometric capacitance of the nanoribbon is charged by ion channel currents. The integration of top-down nanoribbons with electrophysiology holds promise for integration of electrically active living systems with artificial electronics. ...[more]
Similar Datasets
Project description:Electrical sensors have been widely explored for the analysis of chemical/biological species. Ion detection with single charge resolution is the ultimate sensitivity goal of such sensors, which is yet to be experimentally demonstrated. Here, the events of capturing and emitting a single hydrogen ion (H+) at the solid/liquid interface are directly detected using sub–10-nm electrical double layer–gated silicon nanowire field-effect transistors (SiNWFETs). The SiNWFETs are fabricated using a complementary metal-oxide-semiconductor compatible process, with a surface reassembling step to minimize the device noise. An individually activated surface Si dangling bond (DB) acts as the single H+ receptor. Discrete current signals, generated by the single H+-DB interactions via local Coulomb scattering, are directly detected by the SiNWFETs. The single H+-DB interaction kinetics is systematically investigated. Our SiNWFETs demonstrate unprecedented capability for electrical sensing applications, especially for investigating the physics of solid/liquid interfacial interactions at the single charge level.
| S-EPMC8641926 | biostudies-literature
Project description:The acid-sensing ion channels (ASICs) are a family of proton-sensing channels expressed throughout the nervous system. Their activity is linked to a variety of complex behaviors including fear, anxiety, pain, depression, learning, and memory. ASICs have also been implicated in neuronal degeneration accompanying ischemia and multiple sclerosis. As a whole, ASICs represent novel therapeutic targets for several clinically important disorders. An understanding of the correlation between ASIC structure and function will help to elucidate their mechanism of action and identify potential therapeutics that specifically target these ion channels. Despite the seemingly simple nature of proton binding, multiple studies have shown that proton-dependent gating of ASICs is quite complex, leading to activation and desensitization through distinct structural components. This review will focus on the structural aspects of ASIC gating in response to both protons and the newly discovered activators GMQ and MitTx. ASIC modulatory compounds and their action on proton-dependent gating will also be discussed. This review is dedicated to the memory of Dale Benos, who made a substantial contribution to our understanding of ASIC activity.
| S-EPMC3469599 | biostudies-literature
Project description:Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a "sensing" ion channel to "non-sensing," leading to ocular channelopathies like Leber's congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophinopathies, retinitis pigmentosa, etc. We also discuss the various in vitro and in vivo disease models available to investigate the impact of mutations on channel properties, to dissect the disease mechanism, and understand the pathophysiology. Innovating the potential pharmacological and therapeutic approaches and their efficient delivery to the eye for reversing a "non-sensing" channel to "sensing" would be life-changing.
| S-EPMC7554890 | biostudies-literature
Project description:Developments in semiconductor technology are propelling the dimensions of devices down to 10 nm, but facing great challenges in manufacture at the sub-10 nm scale. Nanotechnology can fabricate nanoribbons from two-dimensional atomic crystals, such as graphene, with widths below the 10 nm threshold, but their geometries and properties have been hard to control at this scale. Here we find that robust ultrafine molybdenum-sulfide ribbons with a uniform width of 0.35 nm can be widely formed between holes created in a MoS2 sheet under electron irradiation. In situ high-resolution transmission electron microscope characterization, combined with first-principles calculations, identifies the sub-1 nm ribbon as a Mo5S4 crystal derived from MoS2, through a spontaneous phase transition. Further first-principles investigations show that the Mo5S4 ribbon has a band gap of 0.77 eV, a Young's modulus of 300GPa and can demonstrate 9% tensile strain before fracture. The results show a novel top-down route for controllable fabrication of functional building blocks for sub-nanometre electronics.
| S-EPMC3644098 | biostudies-literature
Project description:Stomatin proteins oligomerize at membranes and have been implicated in ion channel regulation and membrane trafficking. To obtain mechanistic insights into their function, we determined three crystal structures of the conserved stomatin domain of mouse stomatin that assembles into a banana-shaped dimer. We show that dimerization is crucial for the repression of acid-sensing ion channel 3 (ASIC3) activity. A hydrophobic pocket at the inside of the concave surface is open in the presence of an internal peptide ligand and closes in the absence of this ligand, and we demonstrate a function of this pocket in the inhibition of ASIC3 activity. In one crystal form, stomatin assembles via two conserved surfaces into a cylindrical oligomer, and these oligomerization surfaces are also essential for the inhibition of ASIC3-mediated currents. The assembly mode of stomatin uncovered in this study might serve as a model to understand oligomerization processes of related membrane-remodelling proteins, such as flotillin and prohibitin.
| S-EPMC3433786 | biostudies-literature
Project description:Printing technologies are changing the face of electronics with features such as resource-efficiency, low-cost, and novel form factors. While significant advances have been made in terms of organic electronics, the high-performance and stable transistors by printing, and their large-scale integration leading to fast integrated circuits remains a major challenge. This is because of the difficulties to print high-mobility semiconducting materials and the lack of high-resolution printing techniques. Herein, we present silicon based printed n- and p-channel transistors to demonstrate the possibility of developing high-performance complementary metal-oxide-semiconductor (CMOS) computing architecture. The direct roll transfer printing is used here for deterministic assembly of high-mobility single crystal silicon nanoribbons arrays on a flexible polyimide substrate. This is followed by high-resolution electrohydrodynamic printing to define source/drain/gate electrodes and to encapsulate, thus leading to printed devices. The printed transistors show effective peak mobilities of 15 cm2/(V s) (n-channel) and 5 cm2/(V s) (p-channel) at low 1 V drain bias. Furthermore, the effect of electrical, mechanical, and thermal stress on the performance and stability of the encapsulated transistors is investigated. The transistors showed stable transfer characteristics even after: (i) continuous 4000 transfer cycles, (ii) excruciating 10000 bending cycles at different bending radii (40, 25, and 15 mm), and (iii) between 15 and 60 °C temperatures.
| S-EPMC9990968 | biostudies-literature
Project description:Fourier transform mass spectrometers routinely provide high mass resolution, mass measurement accuracy, and mass spectral dynamic range. In this work, we utilize 21 T Fourier transform ion cyclotron resonance (FT-ICR) to analyze product ions derived from the application of multiple dissociation techniques and/or multiple precursor ions within a single transient acquisition. This ion loading technique, which we call, "chimeric ion loading", saves valuable acquisition time, decreases sample consumption, and improves top-down protein sequence coverage. In the analysis of MCF7 cell lysate, we show collision-induced dissociation (CID) and electron-transfer dissociation (ETD) on each precursor on a liquid chromatography-mass spectrometry (LC-MS) timescale and improve mean sequence coverage dramatically (CID-only 15% vs chimeric 33%), even during discovery-based acquisition. This approach can also be utilized to multiplex the acquisition of product ion spectra of multiple charge states from a single protein precursor or multiple ETD/proton-transfer reactions (PTR) reaction periods. The analytical utility of chimeric ion loading is demonstrated for top-down proteomics, but it is also likely to be impactful for tandem mass spectrometry applications in other areas.
| S-EPMC7845485 | biostudies-literature
Project description:The study of bacterial ion channels has provided fundamental insights into the structural basis of neuronal signalling; however, the native role of ion channels in bacteria has remained elusive. Here we show that ion channels conduct long-range electrical signals within bacterial biofilm communities through spatially propagating waves of potassium. These waves result from a positive feedback loop, in which a metabolic trigger induces release of intracellular potassium, which in turn depolarizes neighbouring cells. Propagating through the biofilm, this wave of depolarization coordinates metabolic states among cells in the interior and periphery of the biofilm. Deletion of the potassium channel abolishes this response. As predicted by a mathematical model, we further show that spatial propagation can be hindered by specific genetic perturbations to potassium channel gating. Together, these results demonstrate a function for ion channels in bacterial biofilms, and provide a prokaryotic paradigm for active, long-range electrical signalling in cellular communities.
| S-EPMC4890463 | biostudies-literature
Project description:Narrow atomically precise graphene nanoribbons hold great promise for electronic and optoelectronic applications, but the previously demonstrated nanoribbon-based devices typically suffer from low currents and mobilities. In this study, we explored the idea of lateral extension of graphene nanoribbons for improving their electrical conductivity. We started with a conventional chevron graphene nanoribbon, and designed its laterally extended variant. We synthesized these new graphene nanoribbons in solution and found that the lateral extension results in decrease of their electronic bandgap and improvement in the electrical conductivity of nanoribbon-based thin films. These films were employed in gas sensors and an electronic nose system, which showed improved responsivities to low molecular weight alcohols compared to similar sensors based on benchmark graphitic materials, such as graphene and reduced graphene oxide, and a reliable analyte recognition. This study shows the methodology for designing new atomically precise graphene nanoribbons with improved properties, their bottom-up synthesis, characterization, processing and implementation in electronic devices.Atomically precise graphene nanoribbons are a promising platform for tailored electron transport, yet they suffer from low conductivity. Here, the authors devise a strategy to laterally extend conventional chevron nanoribbons, thus achieving increased electrical conductivity and improved chemical sensing capabilities.
| S-EPMC5635063 | biostudies-literature
Project description:Zinc is an essential biological trace element. It is required for the structure or function of over 300 proteins, and it is increasingly recognized for its role in cell signaling. However, high concentrations of zinc have cytotoxic effects, and overexposure to zinc can cause pain and inflammation through unknown mechanisms. Here we show that zinc excites nociceptive somatosensory neurons and causes nociception in mice through TRPA1, a cation channel previously shown to mediate the pungency of wasabi and cinnamon through cysteine modification. Zinc activates TRPA1 through a unique mechanism that requires zinc influx through TRPA1 channels and subsequent activation via specific intracellular cysteine and histidine residues. TRPA1 is highly sensitive to intracellular zinc, as low nanomolar concentrations activate TRPA1 and modulate its sensitivity. These findings identify TRPA1 as an important target for the sensory effects of zinc and support an emerging role for zinc as a signaling molecule that can modulate sensory transmission.
| S-EPMC2677965 | biostudies-literature