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Zeng P, Zheng M, Chen H, Chen G, Shu Z, Chen L, Liang H, Zhou Y, Zhao Q, Duan H. Wafer-Level Highly Dense Metallic Nanopillar-Enabled High-Performance SERS Substrates for Molecular Detection. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13111733. [PMID: 37299638 DOI: 10.3390/nano13111733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023]
Abstract
Seeking sensitive, large-scale, and low-cost substrates is highly important for practical applications of surface-enhanced Raman scattering (SERS) technology. Noble metallic plasmonic nanostructures with dense hot spots are considered an effective construction to enable sensitive, uniform, and stable SERS performance and thus have attracted wide attention in recent years. In this work, we reported a simple fabrication method to achieve wafer-scale ultradense tilted and staggered plasmonic metallic nanopillars filled with numerous nanogaps (hot spots). By adjusting the etching time of the PMMA (polymethyl methacrylate) layer, the optimal SERS substrate with the densest metallic nanopillars was obtained, which possessed a detection limit down to 10-13 M by using crystal violet as the detected molecules and exhibited excellent reproducibility and long-term stability. Furthermore, the proposed fabrication approach was further used to prepare flexible substrates; for example, a SERS flexible substrate was proven to be an ideal platform for analyzing low-concentration pesticide residues on curved fruit surfaces with significantly enhanced sensitivity. This type of SERS substrate possesses potential in real-life applications as low-cost and high-performance sensors.
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Affiliation(s)
- Pei Zeng
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | | | - Hao Chen
- Jihua Laboratory, Foshan 528000, China
| | | | - Zhiwen Shu
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, China
- Greater Bay Area Innovation Institute, Hunan University, Guangzhou 511300, China
| | - Lei Chen
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, China
- Greater Bay Area Innovation Institute, Hunan University, Guangzhou 511300, China
| | - Huikang Liang
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, China
- Greater Bay Area Innovation Institute, Hunan University, Guangzhou 511300, China
| | - Yuting Zhou
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Beijing 100084, China
| | - Qian Zhao
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Huigao Duan
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, China
- Greater Bay Area Innovation Institute, Hunan University, Guangzhou 511300, China
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Zeng P, Zhou Y, Shu Z, Liang H, Zhang X, Chen Y, Duan H, Zheng M. Suspended 3D metallic dimers with sub-10 nm gap for high-sensitive SERS detection. NANOTECHNOLOGY 2022; 34:095301. [PMID: 36384034 DOI: 10.1088/1361-6528/aca338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
The suspended metallic nanostructures with tiny gaps have certain advantages in surface-enhanced Raman scattering (SERS) due to the coaction of the tiny metallic nanogaps and the substrate-decoupled electromagnetism resonant modes. In this study, we used the lithographic HSQ/PMMA electron-beam bilayer resist exposure combined with a deposition-induced nanogap-narrowing process to define elevated suspended metallic nanodimers with tiny gaps for surface-enhanced Raman spectroscopy detection. By adjusting the deposited metal thickness, the metallic dimers with sub-10 nm gaps can be reliably obtained. These dimers with tunable nanogaps successfully served as excellent SERS substrates, exhibiting remarkable high-sensitivity detection ability for crystal violet molecules. Systematic experiments and simulations were conducted to explain the origin of the improved SERS performance. The results showed that the 3D elevated suspended metallic dimers could achieve a higher SERS enhancement factor than the metallic dimers on HSQ pillars and a common Si substrate, demonstrating that this kind of suspended metallic dimer is a promising route for high-sensitive SERS detection and other plasmonic applications.
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Affiliation(s)
- Pei Zeng
- Jihua Laboratory, Foshan 528000, People's Republic of China
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Yuting Zhou
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Zhiwen Shu
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Huikang Liang
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Xiaoqing Zhang
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Yiqin Chen
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Huigao Duan
- College of Mechanical and Vehicle Engineering, National Engineering Research Centre for High Efficiency Grinding, Hunan University, Changsha 410082, People's Republic of China
| | - Mengjie Zheng
- Jihua Laboratory, Foshan 528000, People's Republic of China
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