Quynh Nhu Nguyen Thi, Thi Le Tran Thanh, Hung Le Vu Tuan, Hsiao Vincent K S
Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan.
Department of Applied Physics, Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh City 748000, Vietnam.
Materials (Basel). 2025 Jul 13;18(14):3299. doi: 10.3390/ma18143299.
This study investigates the effects of substrate flexibility and metal deposition methods on piezoelectric-enhanced Surface-Enhanced Raman Scattering (SERS) in metal-deposited ZnO nanorod (NR) nanocomposites (NCPs). ZnO NRs were grown on both rigid (ITO-glass) and flexible (ITO-PET) substrates, followed by gold (Au) deposition by pulsed-laser-induced photolysis (PLIP) or silver (Ag) deposition by thermal evaporation. Structural analysis revealed that ZnO NRs on flexible substrates exhibited smaller diameters (60-80 nm vs. 80-100 nm on glass), a higher density, and diverse orientations that enhanced piezoelectric responsiveness. Optical characterization showed distinct localized surface plasmon resonance (LSPR) peaks at 420 nm for Ag and 525 nm for Au systems. SERS measurements demonstrated that Ag-ZnO NCPs achieved superior detection limits (10 M R6G) with enhancement factors of 10-10, while Au-ZnO NCPs reached 10 M detection limits. Mechanical bending of flexible substrates induced dramatic signal enhancement (50-100-fold for Au-ZnO/PET and 2-3-fold for Ag-ZnO/PET), directly confirming piezoelectric enhancement mechanisms. This work establishes quantitative structure-property relationships in piezoelectric-enhanced SERS and provides design principles for high-performance flexible sensors.
本研究考察了基底柔韧性和金属沉积方法对金属沉积的氧化锌纳米棒（NR）纳米复合材料（NCP）中压电增强表面增强拉曼散射（SERS）的影响。氧化锌纳米棒生长在刚性（ITO玻璃）和柔性（ITO聚对苯二甲酸乙二酯）基底上，随后通过脉冲激光诱导光解（PLIP）沉积金（Au）或通过热蒸发沉积银（Ag）。结构分析表明，柔性基底上的氧化锌纳米棒直径较小（60 - 80纳米，而玻璃上为80 - 100纳米）、密度更高且取向多样，这增强了压电响应性。光学表征显示，银体系在420纳米处和金体系在525纳米处有明显的局域表面等离子体共振（LSPR）峰。SERS测量表明，银 - 氧化锌NCP实现了卓越的检测限（10⁻¹⁰ M罗丹明6G），增强因子为10⁸ - 10¹⁰，而金 - 氧化锌NCP达到了10⁻⁸ M的检测限。柔性基底的机械弯曲导致信号显著增强（金 - 氧化锌/聚对苯二甲酸乙二酯增强50 - 100倍，银 - 氧化锌/聚对苯二甲酸乙二酯增强2 - 3倍），直接证实了压电增强机制。这项工作建立了压电增强SERS中的定量结构 - 性能关系，并为高性能柔性传感器提供了设计原则。
