Recent Papers Organized by Topic

Boron Nitride Nanotubes and Phonon Polaritons:

Kim, K. S.; Gilburd, L.; Ho, K.; Trajanoski, D.; Maiti, A.; Halverson, D.; van der Velden, L.; de Beer, S.; Walker, G. C. “The Effect of Adjacent Materials on the Propagation of Phonon Polaritons in Hexagonal Boron Nitride“, J Phys. Chem. Lett., 2017.

Gilburd, L.; Kim, K. S.; Ho, K.; Trajanoski, D.; Maiti, A.; Halverson, D.; de Beer, S.; Walker, G. C. “Hexagonal Boron Nitride Self-Launches Hyperbolic Phonon Polaritons”, J Phys. Chem. Lett., 2017, 8, 2158–2162. 

Gilburd, L.;  Xu, X. G.; Bando,Y. Golberg, D.; Walker, G C. “Surface Phonon Coupling within Boron Nitride Nanotubes Resolved by a Novel Near-Field Infrared Pump-Probe Imaging Technique”, Microsc. Microanal., 2016, 22, 366-367.

Xu, X. G.; Gilburd, L.; Bando, Y.; Golberg, D.; Walker, G. C. “Defects and Deformation of Boron Nitride Nanotubes Studied by Joint Nanoscale Mechanical and Infrared Near-Field Microscopy,” J. Phys. Chem. C, 2016, DOI: 10.1021/acs.jpcc.5b10670

Xu, X. G.; Ghamsari, B. G.; Jiang, J-H.; Gilburd, L.; Andreev,G. O.;  Zh, C., Bando, J.; Golberg, D.;  Berini,P.; Walker, G. C.“One-dimensional Surface Phonon Polaritons in Boron Nitride Nanotubes,” Nature Comm.20145, 4782.

Ghamsari, B. G.;  Xu, X. G.; Gilburd, L.;  Walker, G. C.; Berini, P. “Mid-Infrared Surface Phonon Polaritons  in Boron-Nitride Nanotubes,” J. Optics, 2014, 16, 114008.

Xu, X. G.; Jiang, J.-H.; Gilburd, L.; Rensing, R. G.; Burch, K. S.; Zhi, C.; Bando, Y.; Golberg, D.; Walker, G. C.  “Mid-Infrared Polaritonic Coupling Between Boron Nitride Nanotubes and Graphene,” ACS Nano20148, 11305–11312.

Tanur, A.; Wang, J.; Leela M.R.A.; Lamont, D.; Yap, Y. K.; Walker, G. C. “Diameter-Dependent Bending Modulus of Individual Multiwall Boron Nitride Nanotubes,” J. Phys. Chem. C, 2013, 117, 4618-4625.

Xu, X. G.; Tanur, A. E.; Walker, G. C.  “Phase Controlled Homodyne Infrared Near-Field Microscopy and Spectroscopy Reveal Inhomogeneity within and among Individual Boron Nitride Nanotubes,” J. Phys. Chem. A, 2013, 117, 3348-3354.

Reddy, A. M. R.; Gupta, B.K.; Narayanan, T. N.; Martí, A.; Ajayan, P.; Walker, G. C. “Probing on Time-Resolved and Photoluminescence Spectroscopy of Ni Encapsulated Ferromagnetic Boron Nitride Nanotubes,” J. Phys. Chem. C, 2012, 116, 12803–12809.

Reddy, A.L.M.; Tanur, A. E.; Walker, G. C. “Synthesis and hydrogen storage properties of different types of boron nitride nanostructures,” Int. J. Hydrogen. Energy,2010, 35, 4138-4143.

A Tool for Nanoscale IR Imaging:

Gilburd, L.; Xu, X. G.; Bando, Y.; Golberg, D.; Walker, G. C. “Near-Field Infrared Pump-Probe Imaging of Surface Phonon Coupling in Boron Nitride Nanotubes,” J. Phys. Chem. Lett. 2016, 7, 289–294.

Xu, X.; Gilburd, L., Walker, G. C. “Phase Stabilized Homodyne of Infrared Scattering Type Scanning Near-field Optical Microscopy,” Appl. Phys. Lett.,2014105, 263104.

Xu, X.; Walker, G. C. Method to obtain absorption spectra from near-field infrared scattering using homodyne detection. US Patent granted December 2013, US8646110 B1.  

Coupled Plasmonic Structures and their Analogues:

Stewart, A.F.; Lee, A.; Ahmed, A.; Ip, S.; Kumacheva, E.; Walker, G.C. “Rational Design for the Controlled Aggregation of Gold Nanorods via Phospholipid Encapsulation for Enhanced Raman Scattering,” ACS Nano20148, 5462-5467.

Klinkova, A.; Thérien-Aubin, H.; Ahmed, A. ; Nykypanchuk, D.; Choueiri, R. ; Gagnon, B.; Muntyanu,  A.; Gang, O.;  Walker, G. C.; Kumacheva, E. “Structural and Optical Properties of Self-Assembled Chains  of Plasmonic Nanocubes,”  Nano Letters2014,  14,  6314–6321.

Pirotta, S.; Xu, X.; Delfan, A.; Mysore, S.; Maiti, S.; Dacarro, G.; Patrini, M.; Galli, M.; Guizzetti, G.; Bajoni, D.; Sipe, J.; Walker, G.C.; Liscidini, M.  “Surface-Enhanced Raman Scattering in Purely Dielectric Structures via Bloch Surface Waves,” J. Phys. Chem. C, 2013, 117, 6821-6825.

Zamecnik, C.; Ahmed, A.; Walters, C.; Gordon, R.; Walker, G. C. “SERS using Lipid Encapsulated Plasmonic Nanoparticles and J-Aggregates to Create Locally Enhanced Electric Fields,” J. Phys. Chem. C, 2013, 117, 1879-1886.

Kofke, M. J; Waldeck, D H.; Walker, G.C. “Composite nanoparticle nanoslit arrays: A novel platform for LSPR mediated subwavelength optical transmission,” Opt. Lett., 2010, 18, 7705-7713.

SERS Particles to Identify Cell Surface Proteins for Biodiagnostics

MacLaughlin, C.; Mullaithilaga, N.; Yang, G.; Ip, S.; Wang, C.; Walker, G. C. “Surface Enhanced Raman Scattering Dye Labeled Au Nanoparticles for Triplexed Detection of Leukemia and Lymphoma Cells and SERS Flow Cytometry,” Langmuir, 2013,29, 1908-1919.

MacLaughlin, C.M.; Parker, E.P.K.; Wang, C.; Walker, G.C. “Evaluation of SERS Labeling of CD20 Using Optical Microscopy and Fluorescence Flow Cytometry,”Nanomedicine, 2013, 9, 55–64.

Ip, S. Y.; MacLaughlin, C. M.; Mullaithilaga, N.;  Joseph, M.; Wala, S.; Wang, C.; Walker, G. C. “Lipid-encapsulation of Surface Enhanced Raman Scattering (SERS) Nanoparticles and Targeting to Chronic Lymphocytic Leukemia (CLL) Cells,”Frontiers in Biological Detection: From Nanosensors to Systems IV. Edited by Miller, Benjamin L.; Fauchet, Philippe M.Proceedings of the SPIE, 2012, 8212, 821204-821204-12.

MacLaughlin, C.M., Parker, E. P. K., Wang, C., Walker, G.C.  “Polymer Coated Surface-enhanced Raman Scattering (SERS) Gold Nanoparticles for Multiplexed Labeling of Chronic Lymphocytic Leukemia Cells,” Frontiers in Biological Detection: From Nanosensors to Systems IV. Edited by Miller, Benjamin L.; Fauchet, Philippe M. Proceedings of the SPIE, 2012, 8212 821203-821203-11.

Ip, S.; MacLaughlin, C. M.; Gunari, N.; Walker, G. C. “Phospholipid membrane encapsulation of nanoparticle for surface enhanced Raman scattering,” Langmuir,2011, 27, 7024-7033.

Nguyen, C.; Nguyen, J.; Rutledge, S.; Zheng, J.; Wang, C.; Walker, G. “Detection of Chronic Lymphocytic Leukemia Cell Surface Markers using Surface Enhanced Raman Scattering Gold Nanoparticles,” Cancer Lett., 2010, , 292, 91-97.

Ip, S.; MacLaughlin, C. M.; Nguyen, Collin, T.; Walker, G. C. “Photonic Nanoparticles for Cellular and Tissular Labeling,” in Biological Nanoscience, Vol. 2 , Walker, G. C ; Krueger, B., eds., of Comprehensive Nanoscience and Nanotechnology, Andrews, D.; Scholes, G.; Wiederrecht, G, eds. (Elsevier, London), 2010; 59-104.

Mechanics of Cellular Environments, including Phospholipid Bilayers

Alipour,E.; Halverson,D.; McWhirter, S.; Walker, G. C. “Phospholipid Bilayers: Stability and Encapsulation of Nanoparticles,” Ann. Rev. Phys. Chem201768, 261-283.

Navab, R.; Strumpf, D.; To, C.; Pasko, E.; Kim, K. S.; Park, C. J.; Hai, J.; Liu, J.; Jonkman, J.; Barczyk, M.; Bandarchi, B.; Wang, Y. H.; Venkat, K.; Ibrahimov, E.; Pham, N.-A.; Ng, C.; Radulovich, N.; Zhu, C.-Q.; Pintillie, M.; Wang, D.; Lu, A.; Jurisica, I.; Walker, G. C.; Gullberg, D.; Tsao, M.-S.  “Integrin α11β1 Regulates Cancer Stromal Stiffness and Promotes Tumorigenicity and Metastasis in Non-Small Cell Lung Cancer,” Oncogene 2015, 35, 1899–1908.

Sullan, R.M.A.; Shi, W.; Chan, H.; Li, J.K.; Walker, G.C. “Mechanical Stability of Phase-Segregated Multicomponent Lipid Bilayers Enhanced by PS-b-PEO Diblock Copolymers,” Soft Matter, 2013, 9, 6245-6253.

Kumachev, A.; Tumarkin, E.; Walker, G. C.; Kumacheva, E. “Characterization of the Mechanical Properties of Microgels Acting as Cellular Microenvironments,” Soft Matter, 2013, 9, 2959-2965.

Velasco, D.; Chau, M.; Therien-Aubin, H.; Kumachev, A.; Tumarkin, E.; Walker, G. C.; Jia, Z.; Monteiro, M.; Kumacheva, E.  “Thermoreversible and Nanofibrillar Micellar Microgels,” Soft Matter, 2013, 9, 2380-2383.

Li, J. K; Sullan, R. M. A.; Zou, S.; Li, I. T. S.; Sun, Y.; Walker, G. C. “Polymer Nanomechanics,” in Polymer Science: A Comprehensive Reference, Matyjaszewski, K.; Möller, M. eds. (London: Academic Press), 2012, 377-404.

Raz, N.; Li, J.; Fiddes, L.; Tumarkin, E.; Walker, G.; Kumacheva, E. “Microgels with an Interpenetrating Network Structure as a Model System for Cell Studies,”Macromolecules, 2010, 43, 7277-7281.

Ip, S.; Li, I.; Walker, G. C. “Phase-segregation of untethered zwitterionic model lipid bilayers observed on mercaptoundecanoic acid-modified Au surfaces by AFM imaging and force mapping,” Langmuir, 2010, 26, 11060-11070.

Sullan, R.M.A; Li, J.K.; Hao, C.; Walker, G.C.; Zou, S. “Cholesteral Dependant Nanomechanical Stability of Phase-Segregated Multicomponent Lipid Bilayers,”Biophysical Journal, 2010, 99, 507-516.

New Tools to Characterize Oligomers and Aggregates of Amyloidogenic Peptides:

Bhowmik, D.; MacLaughlin, C. M; Walker, G. C.; Maiti, S. “pH Changes the Aggregation Propensity of Amyloid-β Without Altering the Monomer Conformation,” Chem Phys Phys Chem, 2014, 16, 885-889.

Paulite, M.; Walker, G. C.; Zenobi, R. “Full Spectroscopic Tip-enhanced Raman Imaging of Single Nanotapes Formed from Beta-amyloid(1-40) Peptide Fragments,”ACS Nano, 20137, 911-920.

Paulite, M.; Fakhraai, Z.; Li, I.; Gunari, N.; Tanur, A.; Walker, G. “Imaging Secondary Structure of Individual Amyloid Fibrils of a β2 microglobulin Fragment using Near-Field Infrared Spectroscopy,” J. Am. Chem. Soc, 2011, 133, 7376-7383.

Length Scales of Hydrophobic Hydration

Mondal, J.; Halverson, D.; Li, I. T. S.; Stirnemann, G.; Walker, G. C.; Berne, B. J. “How Osmolytes Influence Hydrophobic Polymer Conformations: A Unified View from Experiment and Theory,” Proc. Nat. Acad. Sci. USA 2015, 112, 9270-9275.

Li, I.T.S.; Walker, G.C. “Single Polymer Studies of Hydrophobic Hydration,” Accounts of Chemical Research, 2012, 45, 2011-2021.

Li, I.T.S.; Walker, G.C. “Signature of Hydrophobic Hydration in a Single Polymer,” Proceedings of the National Academy of Sciences, 2011, 108, 16527-16532.

Li, I.T.S.; Walker, G.C. “Interfacial Free Energy Governs Single Polystyrene Chain Collapse in Water and Aqueous Solutions,”J. Amer. Chem. Soc., 2010, 132, 6530-6540.

Polymer Self-Assembly:

Gonzalez-Alvarez, M. J.; Lin, J.; Guerin, G.; Kim, K. S.; Du, V. A.; Walker, G. C.; Manners, I.; Winnik, M. A. “How a Small Modification of the Corona-Forming Block Redirects the Self-Assembly of Crystalline-Coil Block Copolymers in Solution,” Macromolecules, 201649, 7975-7984.

Feng, C.; Jose Gonzalez-Alvarez, M.; Song, Y.; Li, I.; Zhao, G.; Molev, G.; Guerin, G.; Walker, G. C., Scholes, G. D.; Manners, I.; Winnik, M.A. “Synthesis, Self-assembly and Photophysical Properties of Oligo(2,5-dihexyloxy-1,4-phenylene vinylene)-block-poly(ethylene glycol),” Soft Matter, 2014, 10, 8875 – 8887.

Jia, L.; Zhao, G.; Shi, W.; Coombs, N.; Gourevich, I.; Walker, G.; Guerin, G.; Manners, I.; Winnik, M.  “A Design Strategy for the Hierarchical Fabrication of Colloidal Hybrid Mesostructures,” Nature Comm20145, 3882.

Molev, G.; Lu, Y.; Kim, K.S.; Majdalani, I.C.; Guerin, G.; Petrov, S.; Walker, G.; Manners, I.; Winnik, M.A.  “Organometallic-Polypeptide Diblock Copolymers: Synthesis by Diels-Alder Coupling and Crystallization-Driven Self-Assembly to Uniform Truncated Elliptical Lamellae,” Macromolecules201447, 2604-2615.

Qian, J.; Lu, Y.; Chia, A.; Zhang, M.; Rupar, P. A.; Gunari, N.; Walker, G. C.; Cambridge, G.; He, F.; Guerin, G.; Manners, I.; Winnik, M. A.  “Self-Seeding in One Dimension: A Route to Uniform Fiber-like Nanostructures from Block Copolymers with a Crystallizable Core-Forming Block,” ACS Nano20137, 3754-3766.

Wang, M.; Zhang, M.; Li, J..; Kumar, S.; Walker, G.C.; Scholes, G.D.; Winnik, M.A. “Self-Assembly of Colloidal Quantum Dots on the Scaffold of Triblock Copolymer Micelles,” ACS Applied Materials & Interfaces, 2010, 2, 3160-3169.

Materials to Reduce Biofouling and the Adhesive Cements of Marine Organisms:

Kim, K. S.; Gunari, N.; MacNeil, D.; Finlay, J. A.; Callow, M. E.; Callow, J. C. Walker, G. C. “Aqueous-Based Fabrication of Low-VOC Nanostructured Block Copolymer Films as Potential Marine Antifouling Coatings,” ACS Appl. Mater. Interfaces 2016, 8, 20342–20351.

Sarvothaman, M. K.; Kim, K. S.; Brodersen, P. M.; Walker, G. C.; Wheeler, A. R. “Dynamic Fluoroalkyl Polyethylene Glycol Co-polymers: A New Strategy for Reducing Protein Adhesion in Lab-on-a-Chip Devices,” Adv. Func. Mater., 2015, 25, 506-515.

Gunari, N.; Brewer,L. H.; Bennett, S. M; Sokolova, A.; Kraut, N. D.; Finlay, J. D.; Meyer, A. E.; Walker, G. C.; Wendt, D.E; Callow, M. E.; Callow, J. A.; Bright, F. V.; Detty, M. R. “The Control of Marine Biofouling on Xerogel Surfaces with Nanometer-scale Topography,” Biofouling, 2011, 27, 137-149.

Grozea, C.; Li, I.T.S.; Grozea, D.; Walker, G.C. “Microdomain Orientation of Diblock Copolymer Ultrathin Films Solvent Annealed at Low Temperatures,”Macromolecules, 2011, 44, 3901-3909.

Weinman, C. J.; Gunari, N.; Krishnan, S.; Don,R.; Paik, M. Y.; Sohn, K. E.; Walker, G. C.;Kramer, E. J; Fischer, D. A.;. Ober, C. K, “Protein Adsorption Resistance of Anti-Biofouling Block Copolymers Containing Amphiphilic Side Chains,” Soft Matter, 2010,6, 3237-3243.

Tanur, A. E.; Gunari, N.; Sullan, R. M. A; Kavanagh, C. J., Walker, G. C. “Insights into the composition, morphology, and formation of the calcareous shell of the serpulid Hydroides dianthus,” J. Str. Biol., 2010, 169, 145–160.

Bennet, S. M.; Finlay, J. A..; Gunari, N., Wells, D. D. Meyer, A. E.; Walker, G. C.; Callow, M. E.; Callow, J. A.; Bright, F. V.; Detty, M. R. “The Role of Surface Energy and Water Wettability in Aminoalkyl/ Fluorocarbon/Hydrocarbon-Modified Xerogel Surfaces in the Control of Marine Biofouling,” Biofouling, 2010, 26, 235-246.

Finlay, J. A.; Bennett, S. M.; Brewer, L. A..; Sokolova, A.; Clay, G.; Gunari, N.; Meyer, A. E.; Walker, G. C.; Wendt, D. E.; Callow, M. E.; Callow, J. A.; Dettey, M. R.“Barnacle Settlement and the Adhesion of Protein and Diatom Microfouling to Xerogel Films with Varying Surface Energy and Water Wettability,” Biofouling, 2010, 26, 657-666.

Sullan, R.M.A.; Tanur, A, Chan, Y.; Dickenson, G. H.; Orihuela, B.; Rittschof, D.; Walker, G. C. “Nanoscale structures that contribute to the toughness of barnacle cement,” Biofouling, 2009, 25, 263–275.

Grozea, C.; Gunari, N.; Finlay, J.; Grozea, D.; Lu, Z.-H.; Callow, M.; Callow, J.; Walker, G. “Water-Stable Diblock Polystyrene-block-Poly(2-vinyl pyridine) and Diblock Polystyrene-block-Poly(methyl methacrylate) Cylindrical Patterned Surfaces Inhibit Settlement of Zoospores of the Green Alga Ulva,” Biomacromolecules, 2009, 10, 1004–1012.

Grozea, C. M.; Walker, G. C. “Recent Approaches in Designing Surfaces to Deter Marine Biofouling,” Soft Matter, 2009, 5, 4088 – 4100.