title: Ordering in bio-inorganic hybrid nanomaterials probed by in situ scanning transmission X-ray microscopy.
abstract: Phospholipid bilayer coated Si nanowires are one-dimensional (1D) composites that provide versatile bio-nanoelectronic functionality via incorporation of a wide variety of biomolecules into the phospholipid matrix. The physiochemical behaviour of the phospholipid bilayer is strongly dependent on its structure and, as a consequence, substantial modelling and experimental efforts have been directed at the structural characterization of supported bilayers and unsupported phospholipid vesicles; nonetheless, the experimental studies conducted to date have exclusively involved volume-averaged techniques, which do not allow for the assignment of spatially resolved structural variations that could critically impact the performance of the 1D phospholipid-Si NW composites. In this manuscript, we use scanning transmission X-ray microscopy (STXM) to probe bond orientation and bilayer thickness as a function of position with a spatial resolution of ∼30 nm for Δ9-cis 1,2-dioleoyl-sn-glycero-3-phosphocholine layers prepared Si NWs. When coupled with small angle X-ray scattering measurements, the STXM data reveal structural motifs of the Si NWs that give rise to multi-bilayer formation and enable assignment of the orientation of specific bonds known to affect the order and rigidity of phospholipid bilayers.
authors: Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA. vanbuuren1@llnl.gov.
authors: Jonathan R I
authors: JR
authors: Lee
authors: Michael
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authors: Bagge-Hansen
authors: Ramya
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authors: Tunuguntla
authors: Kyunghoon
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authors: Kim
authors: Mangesh
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authors: Bangar
authors: Trevor M
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authors: Willey
authors: Ich C
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authors: David A
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authors: Kilcoyne
authors: Aleksandr
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authors: van Buuren