We demonstrate long-range enhancement of fluorescence and Raman scattering using a dense random array of Ag nanoislands (AgNIs) coated with column-structured silica (CSS) overlayer of over 100 nm thickness, namely, remote plasmonic-like enhancement (RPE). The CSS layer provides physical and chemical protection, reducing the impact between analyte molecules and metal nanostructures. RPE plates are fabricated with high productivity using sputtering and chemical immersion in gold(I)/halide solution. The RPE plate significantly enhances Raman scattering and fluorescence, even without proximity between analyte molecules and metal nanostructures. The maximum enhancement factors are 10⁷-fold for Raman scattering and 10²-fold for fluorescence. RPE is successfully applied to enhance fluorescence biosensing of intracellular signalling dynamics in HeLa cells and Raman histological imaging of oesophagus tissues. Our findings present an interesting deviation from the conventional near-field enhancement theory, as they cannot be readily explained within its framework. However, based on the phenomenological aspects we have demonstrated, the observed enhancement is likely associated with the remote resonant coupling between the localised surface plasmon of AgNIs and the molecular transition dipole of the analyte, facilitated through the CSS structure. Although further investigation is warranted to fully understand the underlying mechanisms, the RPE plate offers practical advantages, such as high productivity and biocompatibility, making it a valuable tool for biosensing and biomolecular analysis in chemistry, biology, and medicine. We anticipate that RPE will advance as a versatile analytical tool for enhanced biosensing using Raman and fluorescence analysis in various biological contexts.

我们使用涂有厚度超过 100 nm 的柱状结构二氧化硅 （CSS） 外层的 Ag 纳米岛 （AgNI） 密集随机阵列展示了荧光和拉曼散射的长距离增强，即远程等离子体样增强 （RPE）。CSS 层提供物理和化学保护，减少分析物分子和金属纳米结构之间的影响。RPE 板使用溅射和化学浸入金 （I）/卤化物溶液中以高生产率制造。RPE 板显著增强了拉曼散射和荧光，即使分析物分子和金属纳米结构之间没有接近。拉曼散射的最大增强因子为 10⁷ 倍，荧光的最大增强因子为 10² 倍。RPE 已成功应用于增强 HeLa 细胞内信号动力学的荧光生物传感和食管组织的拉曼组织学成像。我们的研究结果与传统的近场增强理论存在有趣的偏差，因为它们无法在其框架内轻松解释。然而，根据我们已经证明的现象学方面，观察到的增强可能与 AgNIs 的局部表面等离子体与分析物的分子转变偶极子之间的远程共振耦合有关，这是通过 CSS 结构促进的。尽管需要进一步研究以充分了解潜在机制，但 RPE 板具有实用优势，例如高生产率和生物相容性，使其成为化学、生物学和医学中生物传感和生物分子分析的宝贵工具。 我们预计 RPE 将发展成为一种多功能分析工具，用于在各种生物环境中使用拉曼和荧光分析来增强生物传感。