Scrolling graphene into nanofluidic channels

by Utkur Mirsaidov,  VRSS Mokkapati,   Dipanjan Bhattacharya,   Henrik Andersen,  Michel Bosman,   Barbaros Özyilmazcd and  Paul Matsudaira

Lab Chip, 2013,13, 2874-2878

Scrolling of planar graphene induced by water as a result of the interplay between water capillarity and graphene elasticity leads to the formation of stable nanochannels that encapsulate water and nanoscale objects. These graphene nanochannels are potential nanofluidic platforms for dynamic imaging of nanoscale processes in liquids with Transmission Electron Microscopes (TEMs).

Read online: Royal Society Chemistry

Learn more about Utkur Mirsaidov‘s and Paul Matsudaira‘s research.

Sensing the wavefront of x-ray free-electron lasers using aerosol spheres

by N D Loh, et al

Optics Express 21(10) 12385-12394 (2013)

Hartmann sensors can determine wavefront errors in optical systems by measuring deviated optical paths from carefully positioned lenses. But what if these lenses are randomly inserted, and destroyed immediately after illumination?

Despite such randomness, we show, for the first time, that wavefront properties of the unattenuated intense focus of x- ray free-electron laser can still be computationally assembled to aid optical design.

Pictured above: X-ray pulse fluctuations deduced from diffraction data. Fluctuations in wavefront tilts and intensity of x-ray pulses shown in contour plot above.

Read online: Optics Express.

Learn more about  N D Loh’s research.

Membrane destabilization by monomeric hIAPP observed at the single molecule level by Imaging Fluorescence Correlation Spectroscopy

by Nirmalya Bag, Ashraf Ali, Virander Singh Chauhan, Thorsten Wohland and Aseem Mishra

Chem Commun 2013, 49, 9155–9157

Monomeric hIAPP significantly destabilizes both model and live cell membranes by increasing membrane fluidity. This interaction with membranes happens via carpet formation followed by lipid extraction in a concentration dependent manner and thus we propose that hIAPP aggregation prior to membrane interaction may not be necessary for its cytotoxicity.

‘FCS movie’ of live cell membranes upon exposure to the membrane-active peptide amylin

The lateral diffusion of the cell membrane is mapped by imaging fluorescence correlation spectroscopy (Imaging FCS) with 240 nm spatial resolution and 1 ms temporal resolution over a large membrane area (5´5 mm2). We created a 60-minute FCS time lapse movie to follow membrane dynamics upon interaction with amylin (hIAPP), a peptide involved in insulin secretion. The movie shows how the peptide interacts with the bilayer and changes diffusion patterns with time (blue areas forming with advancing time).

Read online: Royal Society Chemistry.

Learn more about Thorsten Wohland’s research.