Flexible surface-enhanced Raman scattering (SERS) substrates are very promising to meet the needs for real-time and on-field detection in practical applications. However, high-performance flexible SERS substrates often suffer from complexity and high cost in fabrication, limiting their widespread applications. Herein, we developed a facile method to fabricate a flexible multicavity SERS substrate composed of a silver nanoparticle (AgNP)-decorated aluminum hydrous oxide nanoflake array (NFA) grown on a polydimethylsiloxane (PDMS) membrane. Strong plasmon couplings promoted by multiple nanocavities afford high-density hotspots within such a flexible AgNPs@NFA/PDMS film, boosting high SERS sensitivity with an enhancement factor (EF) of ∼1.54 × 10⁹, and a limit of detection (LOD) of ∼7.4 × 10^–13 M for rhodamine 6G (R6G) molecules. Furthermore, benefiting from the high sensitivity, high mechanical stability, and transparency of this substrate, in situ SERS detections of trace thiram and crystal violet (CV) molecules on the surface of cherry tomatoes and fish have been realized, with LODs much lower than the maximum allowable limit in food, demonstrating the great potential of such a flexible substrate in food safety monitoring. More importantly, the preparation processes are very simple and environmentally friendly, and the techniques involved are completely compatible with well-established silicon device technologies. Therefore, large-area fabrication with low cost can be readily realized, enabling the extensive applications of SERS sensors in daily life.

中文翻译：

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基于银纳米粒子装饰的水合氧化铝纳米片阵列的柔性多腔SERS基底，用于高灵敏度原位检测


柔性表面增强拉曼散射（SERS）基板非常有希望满足实际应用中实时和现场检测的需求。然而，高性能柔性SERS基底通常存在制造复杂性和高成本的问题，限制了其广泛应用。在此，我们开发了一种简便的方法来制造柔性多腔SERS基底，该基底由生长在聚二甲基硅氧烷（PDMS）膜上的银纳米颗粒（AgNP）装饰的水合铝纳米片阵列（NFA）组成。多个纳米腔促进的强等离子体耦合在这种柔性 AgNPs@NFA/PDMS 薄膜中提供了高密度热点，提高了高 SERS 灵敏度，增强因子 (EF) 为 ∼1.54 × 10 ⁹ ，并且限制罗丹明 6G (R6G) 分子的检测 (LOD) ∼7.4 × 10 ^–13 M。此外，受益于该基质的高灵敏度、高机械稳定性和透明度，实现了樱桃番茄和鱼表面微量福美双和结晶紫（CV）分子的原位SERS检测，LOD远低于现有技术。食品中的最大允许限量，证明了这种柔性基材在食品安全监测中的巨大潜力。更重要的是，制备过程非常简单且环保，并且所涉及的技术与成熟的硅器件技术完全兼容。因此，可以轻松实现低成本的大面积制造，使SERS传感器在日常生活中得到广泛应用。