Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media
Self-propelled chemical micro/nanomotors (MNMs) have demonstrated considerable potential in targeted drug delivery, (bio)sensing, and environmental remediation due to their autonomous nature and possible intelligent self-targeting behaviors (e.g., chemotaxis and phototaxis). However, these MNMs are...
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MDPI AG
2023-04-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/8/1370 |
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| author | Lingxia Yu Manyi Yang Jianguo Guan Fangzhi Mou |
| author_facet | Lingxia Yu Manyi Yang Jianguo Guan Fangzhi Mou |
| author_sort | Lingxia Yu |
| collection | DOAJ |
| description | Self-propelled chemical micro/nanomotors (MNMs) have demonstrated considerable potential in targeted drug delivery, (bio)sensing, and environmental remediation due to their autonomous nature and possible intelligent self-targeting behaviors (e.g., chemotaxis and phototaxis). However, these MNMs are commonly limited by their primary propulsion mechanisms of self-electrophoresis and electrolyte self-diffusiophoresis, making them prone to quenching in high electrolyte environments. Thus, the swarming behaviors of chemical MNMs in high-electrolyte media remain underexplored, despite their potential to enable the execution of complex tasks in high-electrolyte biological media or natural waters. In this study, we develop ultrasmall tubular nanomotors that exhibit ion-tolerant propulsions and collective behaviors. Upon vertical upward UV irradiation, the ultrasmall Fe<sub>2</sub>O<sub>3</sub> tubular nanomotors (Fe<sub>2</sub>O<sub>3</sub> TNMs) demonstrate positive superdiffusive photogravitaxis and can further self-organize into nanoclusters near the substrate in a reversible manner. After self-organization, the Fe<sub>2</sub>O<sub>3</sub> TNMs exhibit a pronounced emergent behavior, allowing them to switch from random superdiffusions to ballistic motions near the substrate. Even at a high electrolyte concentration (<i>C<sub>e</sub></i>), the ultrasmall Fe<sub>2</sub>O<sub>3</sub> TNMs retain a relatively thick electrical double layer (EDL) compared to their size, and the electroosmotic slip flow in their EDL is strong enough to propel them and induce phoretic interactions among them. As a result, the nanomotors can rapidly concentrate near the substrate and then gather into motile nanoclusters in high-electrolyte environments. This work opens a gate for designing swarming ion-tolerant chemical nanomotors and may expedite their applications in biomedicine and environmental remediation. |
| first_indexed | 2024-03-11T04:40:54Z |
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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-03-11T04:40:54Z |
| publishDate | 2023-04-01 |
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| series | Nanomaterials |
| spelling | doaj.art-fc3f716224be4f7da18b535289234acb2023-11-17T20:43:31ZengMDPI AGNanomaterials2079-49912023-04-01138137010.3390/nano13081370Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte MediaLingxia Yu0Manyi Yang1Jianguo Guan2Fangzhi Mou3State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, ChinaState Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, ChinaState Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, ChinaState Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, ChinaSelf-propelled chemical micro/nanomotors (MNMs) have demonstrated considerable potential in targeted drug delivery, (bio)sensing, and environmental remediation due to their autonomous nature and possible intelligent self-targeting behaviors (e.g., chemotaxis and phototaxis). However, these MNMs are commonly limited by their primary propulsion mechanisms of self-electrophoresis and electrolyte self-diffusiophoresis, making them prone to quenching in high electrolyte environments. Thus, the swarming behaviors of chemical MNMs in high-electrolyte media remain underexplored, despite their potential to enable the execution of complex tasks in high-electrolyte biological media or natural waters. In this study, we develop ultrasmall tubular nanomotors that exhibit ion-tolerant propulsions and collective behaviors. Upon vertical upward UV irradiation, the ultrasmall Fe<sub>2</sub>O<sub>3</sub> tubular nanomotors (Fe<sub>2</sub>O<sub>3</sub> TNMs) demonstrate positive superdiffusive photogravitaxis and can further self-organize into nanoclusters near the substrate in a reversible manner. After self-organization, the Fe<sub>2</sub>O<sub>3</sub> TNMs exhibit a pronounced emergent behavior, allowing them to switch from random superdiffusions to ballistic motions near the substrate. Even at a high electrolyte concentration (<i>C<sub>e</sub></i>), the ultrasmall Fe<sub>2</sub>O<sub>3</sub> TNMs retain a relatively thick electrical double layer (EDL) compared to their size, and the electroosmotic slip flow in their EDL is strong enough to propel them and induce phoretic interactions among them. As a result, the nanomotors can rapidly concentrate near the substrate and then gather into motile nanoclusters in high-electrolyte environments. This work opens a gate for designing swarming ion-tolerant chemical nanomotors and may expedite their applications in biomedicine and environmental remediation.https://www.mdpi.com/2079-4991/13/8/1370nanomotorsphototaxiscollective behaviorsion tolerancephotocatalysis |
| spellingShingle | Lingxia Yu Manyi Yang Jianguo Guan Fangzhi Mou Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media Nanomaterials nanomotors phototaxis collective behaviors ion tolerance photocatalysis |
| title | Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media |
| title_full | Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media |
| title_fullStr | Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media |
| title_full_unstemmed | Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media |
| title_short | Ultrasmall Fe<sub>2</sub>O<sub>3</sub> Tubular Nanomotors: The First Example of Swarming Photocatalytic Nanomotors Operating in High-Electrolyte Media |
| title_sort | ultrasmall fe sub 2 sub o sub 3 sub tubular nanomotors the first example of swarming photocatalytic nanomotors operating in high electrolyte media |
| topic | nanomotors phototaxis collective behaviors ion tolerance photocatalysis |
| url | https://www.mdpi.com/2079-4991/13/8/1370 |
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