1
|
Lee S, Park SM, Jung ED, Zhu T, Pina JM, Anwar H, Wu FY, Chen GL, Dong Y, Cui T, Wei M, Bertens K, Wang YK, Chen B, Filleter T, Hung SF, Won YH, Kim KH, Hoogland S, Sargent EH. Dipole Engineering through the Orientation of Interface Molecules for Efficient InP Quantum Dot Light-Emitting Diodes. J Am Chem Soc 2022; 144:20923-20930. [DOI: 10.1021/jacs.2c09705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Seungjin Lee
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - So Min Park
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Eui Dae Jung
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Tong Zhu
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Joao M. Pina
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Husna Anwar
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Feng-Yi Wu
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Guan-Lin Chen
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Yitong Dong
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Teng Cui
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario M5S 3G8, Canada
| | - Mingyang Wei
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Koen Bertens
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Ya-Kun Wang
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Bin Chen
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Tobin Filleter
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ontario M5S 3G8, Canada
| | - Sung-Fu Hung
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Yu-Ho Won
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon-si 16678, Republic of Korea
| | - Kwang Hee Kim
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon-si 16678, Republic of Korea
| | - Sjoerd Hoogland
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| | - Edward H. Sargent
- Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario M5S 1A4, Canada
| |
Collapse
|
2
|
Rasmussen MH, Holler KR, Baio JE, Jaye C, Fischer DA, Gorb SN, Weidner T. Evidence that gecko setae are coated with an ordered nanometre-thin lipid film. Biol Lett 2022; 18:20220093. [PMID: 35857888 DOI: 10.1098/rsbl.2022.0093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The fascinating adhesion of gecko to virtually any material has been related to surface interactions of myriads of spatula at the tips of gecko feet. Surprisingly, the molecular details of the surface chemistry of gecko adhesion are still largely unknown. Lipids have been identified within gecko adhesive pads. However, the location of the lipids, the extent to which spatula are coated with lipids, and how the lipids are structured are still open questions. Lipids can modulate adhesion properties and surface hydrophobicity and may play an important role in adhesion. We have therefore studied the molecular structure of lipids at spatula surfaces using near-edge X-ray absorption fine structure imaging. We provide evidence that a nanometre-thin layer of lipids is present at the spatula surfaces of the tokay gecko (Gekko gecko) and that the lipids form ordered, densely packed layers. Such dense, thin lipid layers can effectively protect the spatula proteins from dehydration by forming a barrier against water evaporation. Lipids can also render surfaces hydrophobic and thereby support the gecko adhesive system by enhancement of hydrophobic-hydrophobic interactions with surfaces.
Collapse
Affiliation(s)
| | | | - Joe E Baio
- The School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, USA
| | - Cherno Jaye
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Daniel A Fischer
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
3
|
Holler KR, Rasmussen MA, Baio JE, Jaye C, Fischer DA, Gorb SN, Weidner T. Structure of Keratins in Adhesive Gecko Setae Determined by Near-Edge X-ray Absorption Fine Structure Spectromicroscopy. J Phys Chem Lett 2022; 13:2193-2196. [PMID: 35230827 DOI: 10.1021/acs.jpclett.2c00004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Geckos have the astonishing ability to climb on vertical surfaces due to the adhesive properties of fibrous setae at the tips of their toe pads. While the adhesion mechanism principle, based on van der Waals interactions of myriads of spatula located at the outermost end of the setal arrays, has been studied extensively, there are still open questions about the chemistry of gecko setae. The gecko adhesive system is based on keratin fibrils assembled to support the entire setal structure. At the same time, the structure and alignment of keratin molecules within the ultrafine spatula tissue, which can support the enormous mechanical strain, still remain unknown. We have studied the molecular structure of gecko spatula using near-edge X-ray absorption fine structure (NEXAFS) imaging. We indeed found that the setae consist of a β-sheet structure aligned with the adhesion direction of the setae. Such alignment may provide mechanical stability to the setae and resistance to wear across different length scales.
Collapse
Affiliation(s)
| | | | - Joe E Baio
- The School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, Oregon 97331, United States
| | - Cherno Jaye
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Daniel A Fischer
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, 24118 Kiel, Germany
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
4
|
Baio JE, Jaye C, Sullivan E, Rasmussen MH, Fischer DA, Gorb S, Weidner T. NEXAFS imaging to characterize the physio-chemical composition of cuticle from African Flower Scarab Eudicella gralli. Nat Commun 2019; 10:4758. [PMID: 31628305 PMCID: PMC6802387 DOI: 10.1038/s41467-019-12616-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/18/2019] [Indexed: 11/30/2022] Open
Abstract
The outermost surface of insect cuticle is a high-performance interface that provides wear protection, hydration, camouflage and sensing. The complex and inhomogeneous structure of insect cuticle imposes stringent requirements on approaches to elucidate its molecular structure and surface chemistry. Therefore, a molecular understanding and possible mimicry of the surface of insect cuticle has been a challenge. Conventional optical and electron microscopies as well as biochemical techniques provide information about morphology and chemistry but lack surface specificity. We here show that a near edge X-ray absorption fine structure microscope at the National Synchrotron Light Source can probe the surface chemistry of the curved and inhomogeneous cuticle of the African flower scarab. The analysis shows the distribution of organic and inorganic surface species while also hinting at the presence of aragonite at the dorsal protrusion region of the Eudicella gralli head, in line with its biological function. Biology serves as inspiration in materials development; this requires improved understanding of the surface chemistry responsible for processes which are being mimicked. Here, the authors report on the use of near edge X-ray absorption fine structure (NEXAFS) imaging to analyze the surface chemistry of insect cuticle.
Collapse
Affiliation(s)
- Joe E Baio
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, USA
| | - Cherno Jaye
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | | | - Daniel A Fischer
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Stanislav Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, 24118, Kiel, Germany
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000, Aarhus C, Denmark.
| |
Collapse
|
5
|
|
6
|
Perera SD, Urquhart SG. Systematic Investigation of π–π Interactions in Near-Edge X-ray Fine Structure (NEXAFS) Spectroscopy of Paracyclophanes. J Phys Chem A 2017; 121:4907-4913. [DOI: 10.1021/acs.jpca.7b03823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sahan D. Perera
- Department of Chemistry, University of Saskatchewan, Treaty Six
Territory, Saskatoon, Saskatchewan, Canada S7N 5C9
| | - Stephen G. Urquhart
- Department of Chemistry, University of Saskatchewan, Treaty Six
Territory, Saskatoon, Saskatchewan, Canada S7N 5C9
| |
Collapse
|
7
|
Baio JE, Spinner M, Jaye C, Fischer DA, Gorb SN, Weidner T. Evidence of a molecular boundary lubricant at snakeskin surfaces. J R Soc Interface 2016; 12:20150817. [PMID: 26655468 DOI: 10.1098/rsif.2015.0817] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
During slithering locomotion the ventral scales at a snake's belly are in direct mechanical interaction with the environment, while the dorsal scales provide optical camouflage and thermoregulation. Recent work has demonstrated that compared to dorsal scales, ventral scales provide improved lubrication and wear protection. While biomechanic adaption of snake motion is of growing interest in the fields of material science and robotics, the mechanism for how ventral scales influence the friction between the snake and substrate, at the molecular level, is unknown. In this study, we characterize the outermost surface of snake scales using sum frequency generation (SFG) spectra and near-edge X-ray absorption fine structure (NEXAFS) images collected from recently shed California kingsnake (Lampropeltis californiae) epidermis. SFG's nonlinear optical selection rules provide information about the outermost surface of materials; NEXAFS takes advantage of the shallow escape depth of the electrons to probe the molecular structure of surfaces. Our analysis of the data revealed the existence of a previously unknown lipid coating on both the ventral and dorsal scales. Additionally, the molecular structure of this lipid coating closely aligns to the biological function: lipids on ventral scales form a highly ordered layer which provides both lubrication and wear protection at the snake's ventral surface.
Collapse
Affiliation(s)
- Joe E Baio
- School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - Marlene Spinner
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten, Kiel 24118, Germany
| | - Cherno Jaye
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Daniel A Fischer
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Stanislav N Gorb
- Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten, Kiel 24118, Germany
| | - Tobias Weidner
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
| |
Collapse
|