title: Quantitative Profiling of Nanoscale Liposome Deformation by a Localized Surface Plasmon Resonance Sensor.
abstract: Characterizing the shape of sub-100 nm, biological soft-matter particulates (e.g., liposomes and exosomes) adsorbed at a solid-liquid interface remains a challenging task. Here, we introduce a localized surface plasmon resonance (LSPR) sensing approach to quantitatively profile the deformation of nanoscale, fluid-phase 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes contacting a titanium dioxide substrate. Experimental and theoretical results validate that, due to its high sensitivity to the spatial proximity of phospholipid molecules near the sensor surface, the LSPR sensor can discriminate fine differences in the extent of ionic strength-modulated liposome deformation at both low and high surface coverages. By contrast, quartz crystal microbalance-dissipation (QCM-D) measurements performed with equivalent samples were qualitatively sensitive to liposome deformation only at saturation coverage. Control experiments with stiffer, gel-phase 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes verified that the LSPR measurement discrimination arises from the extent of liposome deformation, while the QCM-D measurements yield a more complex response that is also sensitive to the motion of adsorbed liposomes and coupled solvent along with lateral interactions between liposomes. Collectively, our findings demonstrate the unique measurement capabilities of LSPR sensors in the area of biological surface science, including competitive advantages for probing the shape properties of adsorbed, nanoscale biological particulates.
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Jackman
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.
authors.forename: Saziye
authors.initials: S
authors.lastname: Yorulmaz Avsar
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.
authors.forename: Abdul Rahim
authors.initials: AR
authors.lastname: Ferhan
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.
authors.forename: Danlin
authors.initials: D
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Park
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.|Boreskov Institute of Catalysis, Russian Academy of Sciences , Novosibirsk 630090, Russia.
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Zhdanov
authors.affiliation: School of Materials Science and Engineering and Centre for Biomimetic Sensor Science, Nanyang Technological University , 50 Nanyang Drive, 637553, Singapore.|School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, 637459, Singapore.
authors.forename: Nam-Joon
authors.identifier: 0000-0002-8692-8955
authors.initials: NJ
authors.lastname: Cho