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Ilyas AMO, Alam MK, Musah JD, Saw LO, Venkatesh S, Yeung CC, Yang M, Vellaisamy ALR, Lau C. Development of a carboxyl-terminated indium tin oxide electrode for improving cell adhesion and facilitating low noise, real-time impedance measurements. Am J Physiol Cell Physiol 2021; 320:C974-C986. [PMID: 33689477 DOI: 10.1152/ajpcell.00537.2020] [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: 11/22/2022]
Abstract
The working electrode's surface property is crucial to cell adhesion and signal collection in electric cell-substrate impedance sensing (ECIS). To date, the indium tin oxide (ITO)-based working electrode is of interest in ECIS study due to its high transparency and biocompatibility. Of great concern is the impedance signal loss, distortion, and data interpretation conflict profoundly created by the movement of multiple cells during ECIS study. Here, a carboxyl-terminated ITO substrate was prepared by stepwise surface amino silanization, with N-hydroxy succinimide (NHS) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) treatment, respectively. We investigated the stepwise changes in the property of the treated ITO, cell-substrate adhesion, collective cell mobility, and time course of change in absolute impedance from multiple Chinese hamster ovary (CHO) cells [(Δt-Δ|Z|)CELLS]. The carboxyl-terminated ITO substrate with a surface roughness of 6.37 nm shows enhanced conductivity, 75% visible light transparency, improved cell adherence, reduced collective cell migration speed by approximately twofold, and diminished signal distortion in the [(Δt-Δ|Z|)CELLS]. Thus, our study provides an ITO surface-treatment strategy to reduce multiple cell movement effects and to obtain essential cell information from the ECIS study of multiple cells through undistorted (Δt-Δ|Z|)CELLS.
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Affiliation(s)
- A M Olabisi Ilyas
- Department of Physics, City University of Hong Kong, Kowloon, Special Administrative Region of China.,Department of Physics, Federal University Oye-Ekiti, Oye-Ekiti, Nigeria
| | - Md Kowsar Alam
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Special Administrative Region of China.,Department of Physics, University of Chittagong, Chittagong, Bangladesh
| | - Jamal-Deen Musah
- State Key Laboratory of Terahertz and Millimeter Waves, Department of Material Science and Engineering, City University of Hong Kong, Kowloon, Special Administrative Region of China
| | - Lin Oo Saw
- State Key Laboratory of Terahertz and Millimeter Waves, Department of Material Science and Engineering, City University of Hong Kong, Kowloon, Special Administrative Region of China
| | - Shishir Venkatesh
- State Key Laboratory of Terahertz and Millimeter Waves, Department of Material Science and Engineering, City University of Hong Kong, Kowloon, Special Administrative Region of China
| | - Chi-Chung Yeung
- Department of Chemistry, City University of Hong Kong, Kowloon, Special Administrative Region of China
| | - Mengsu Yang
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Special Administrative Region of China
| | - A L R Vellaisamy
- James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Condon Lau
- Department of Physics, City University of Hong Kong, Kowloon, Special Administrative Region of China
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Duan L, Ji X, Yang Y, Yang S, Lv X, Xie Y. Thickness-dependent fast wetting transitions due to the atomic layer deposition of zinc oxide on a micro-pillared surface. RSC Adv 2020; 10:1120-1126. [PMID: 35494465 PMCID: PMC9048290 DOI: 10.1039/c9ra08498c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 11/29/2019] [Indexed: 11/21/2022] Open
Abstract
Smart surfaces promote the fundamental understanding of wetting and are widely used in practical applications for energy and water collection. Light-induced switchable wettability facilitated by ZnO coatings, for instance, was developed for liquid manipulation at the surface. However, the transition of wetting states was reported to follow a hydrophobic–hydrophilic cycle in an hour, which is very long and may limit its future applications. We recently discovered that the cycle of the wetting state transitions on inorganic coatings can be shortened to less than 100 seconds by using ALD-coated ZnO on a pillared surface. However, the mechanisms are still unclear. Here, we investigated the effects of coating thickness on the transition speed and found that it significantly depended on the thickness of the coating with the optimal thickness less than 50 nm. We found that the minimum critical time for a wetting state transition cycle was less than 50 seconds with a thickness of 40 nm. Although the transition time of surfaces with coatings over 70 nm thickness remained constant at 10 min for a cycle, it was shorter than those of other deposition techniques for a coarse surface. Here, we propose a “penetration–diffusion” model to explain the fast and thickness-dependent wetting transitions. Our study may provide a new paradigm for fast wetting transition surfaces with cycle time within tens of seconds using a homogeneous thin layer coated on a rough surface. Smart surfaces promote the fundamental understanding of wetting and are widely used in practical applications for energy and water collection.![]()
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Affiliation(s)
- Libing Duan
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
| | - Xiangyang Ji
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
| | - Yajie Yang
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
| | - Sihang Yang
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
| | - Xinjun Lv
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
| | - Yanbo Xie
- MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions
- School of Science
- Northwestern Polytechnical University
- Xi'an 710072
- China
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