Bacteria of the Bacillus cereus family form highly resistant spores, which in case pathogen B. anthracis act as agents infection. The outermost layer, exosporium, enveloping spores well a number Clostridia , plays roles spore adhesion, dissemination, targeting, and germination control. We have analyzed two naturally crystalline layers associated with one representing “basal” layer to (“hairy nap”) is attached, other likely subsurface (“parasporal”) layer. used electron cryomicroscopy at...

The physical properties of semicrystalline polymers depend on the organisation chains within crystal and amorphous regions, interface between two, location nature defects. Here, torsional tapping atomic force microscopy has been used to image crystalline lamellae crystal-amorphous-region at single-chain level with resolution down 3.7 Å. Defects phase, such as buried folds chain ends, are revealed. Imaging also allows direct measurement stem lengths, providing a potential route test theories...

Torsional-tapping AFM with supersharp carbon-whisker tips is used to explore the molecular conformations at surface of a semicrystalline polymer. Images crystal–amorphous interface oriented polyethylene have allowed us measure hitherto inaccessible parameters that can be directly compared polymer crystallization theories and simulations, such as length stem-to-stem overhang. It has also been possible identify both first- second-neighbor folds determine roughness lamellae which we find...

The function of bioenergetic membranes is strongly influenced by the spatial arrangement their constituent membrane proteins. Atomic force microscopy (AFM) can be used to probe protein organization at high resolution, allowing individual proteins identified. However, previous AFM studies biological have typically required that curved are ruptured and flattened during sample preparation, with possibility disruption native or loss Imaging native, requires minimal tip–sample interaction in both...

Transition metal dichalcogenides have emerged as promising materials for nanophotonic resonators because of their large refractive index, low absorption within a portion the visible spectrum, and compatibility with wide range substrates. Herein, we use these properties to fabricate WS2 double-pillar nanoantennas in variety geometries enabled by anisotropy crystal structure. Using dark-field spectroscopy, reveal multiple Mie resonances, which couple WSe2 monolayer photoluminescence achieve...

Calibration of lateral forces and displacements has been a long standing problem in force microscopies. Recently, it was shown by Wagner et al. that the thermal noise spectrum first torsional mode may be used to calibrate deflection sensitivity detector. This method is quick, non-destructive performed situ air or liquid. Here we make full quantitative comparison inverse optical lever obtained shape independent developed Anderson We find provides accurate results for wide variety rectangular...

The availability of accessible fabrication methods based on deterministic transfer atomically thin crystals has been essential for the rapid expansion research into van der Waals heterostructures. An inherent issue these techniques is deformation polymer carrier film during transfer, which can lead to highly nonuniform strain induced in transferred two-dimensional material. Here, using a combination optical spectroscopy, atomic force, and Kelvin probe force microscopy, we show that presence...

Clostridium sporogenes is a non-pathogenic close relative and surrogate for Group I (proteolytic) neurotoxin-producing botulinum strains. The exosporium, the sac-like outermost layer of spores these species, likely to contribute adhesion, dissemination, virulence. A paracrystalline array, hairy nap, several appendages were detected in exosporium C. strain NCIMB 701792 by EM AFM. protein composition purified was explored LC-MS/MS tryptic peptides from major individual SDS-PAGE-separated...

Spores, the infectious agents of many Firmicutes, are remarkably resilient cell forms. Even distant relatives can have similar spore architectures although some display unique features; they all incorporate protective proteinaceous envelopes. We previously found that Bacillus spores achieve these properties through extensive disulfide cross-linking self-assembled arrays cysteine-rich proteins. predicted this could be a mechanism employed by formers in general, even those from other genera....

An atomic force microscope for use in liquids including water, which a torsionally resonating microcantilever controls the tip-sample interaction, is presented. Magnetostrictive actuators made from particulate composite of Terfenol-D are used to excite torsional oscillations cantilever. The high quality factor (Q) oscillation gives sensitivity forces, and ability work using true resonance peak cantilever allows “phase” images corresponding real mechanical contrast be collected under liquid....

The mode of liquid crystal (LC) self-assembly asymmetric three-arm star oligobenzoate mesogens has been investigated by torsional tapping AFM imaging, and bulk grazing-incidence X-ray diffraction. It was confirmed that the cubic phase Imm symmetry established it consists spherical aggregates arranged on a body-centered lattice, rather than having bicontinuous structure. Molecular simulation suggests that, in spite their perceived rigidity, are folded, often sharply, within supramolecular...

Torsional oscillation of atomic force microscope cantilevers has been shown to offer increased optical lever sensitivity, quality factor, resonant frequency, and stiffness as compared flexural oscillation. In this letter, T-shaped are oscillated torsionally give a tapping motion at the tip. This gives many advantages small cantilevers, without requirement for specialized detection optics. order demonstrate capability technique, high resolution images LH2 membrane protein crystal structures...

The metastatic tumour growing in bone is mechanically distinct from both its surrounding environment and vitro models.

Scanning probe microscopy (SPM) techniques can obtain nanoscale images of soft materials in almost any environment and over a wide range temperatures. Being non-destructive, processes such as crystallization be followed in-situ, the effect changes temperature on structures monitored at nanometre scale. The application these recent years has lead to real change our understanding many fundamental processes. capabilities scanning microscopes are continuously being enhanced, with developments...

We show that sequential protein deposition is possible by photodeprotection of films formed from a tetraethylene-glycol functionalized nitrophenylethoxycarbonyl-protected aminopropyltriethoxysilane (NPEOC-APTES). Exposure to near-UV irradiation removes the protein-resistant protecting group, and allows adsorption onto resulting aminated surface. The resistance was tested using proteins with fluorescent labels microspectroscopy two-component structures micro- nanopatterning yellow green...

Integrating photovoltaic devices onto the surface of carbon-fiber-reinforced polymer substrates should create materials with high mechanical strength that are also able to generate electrical power. Such anticipated find ready applications as structural, energy-harvesting systems in both automotive and aeronautical sectors. Here, fabrication triple-cation perovskite n-i-p solar cells planarized is demonstrated, utilizing a transparent top ITO contact. These contain "wrinkled" SiO

A comprehensive scanning probe microscopy study has been carried out to characterise 3,4,9,10-Perylenetetracarboxylic diimide (PTCDI)-melamine hydrogen-bonded networks deposited on Au(111)-surfaces. Both tunnelling and atomic force were utilized. Such complementary analysis revealed a multilayered structure of the Au(111)-surface as opposed widely reported monolayer structure. Details network formation mechanism are presented. We have also demonstrated that despite apparent stability in...

We report an x-shaped plasmonic antenna design patterned onto the gold coated facet of a mid-infrared quantum cascade laser. Using apertureless scanning near-field optical microscopy we measure single enhanced region in at center x-antenna, with full-width-at-half-maximum ∼100 nm for operating wavelength ∼8.8 μm. This provides complete suppression signal away from center, concomitant improvements imaging contrast expected. Our experimental results are also good agreement finite difference...

A high-speed atomic force microscope for scanning large areas, utilizing a quartz bar driven close to resonance provide the motion in fast scan axis is presented. Images up 170 × μm2 have been obtained on polydimethylsiloxane (PDMS) grating 1 s. This provided through an average tip-sample velocity of 28 cm s-1 at line rate 830 Hz. Scan areas 80 0.42 s with 1410 To demonstrate capability scanner spherulitic crystallization semicrystalline polymer was imaged situ high speed.

We report the results of transmission experiments performed on hybridized plasmonic metamaterial quantum cascade lasers. This device was formed by etching an array split ring resonators (SRRs) onto gold coated facet a laser. Broadband midinfrared confirm resonant nature SRR structure, in good agreement with finite-difference time-domain calculations and from structures fabricated bare GaAs. The long fundamental resonance observed at lambda ~ 6.3 μm. These devices have potential uses...