Herein, we report a facile strategy of combined SERS measurements based on a split-type SERS substrate, which exhibits excellent SERS activity, detection signal reproducibility and chemical stability. The SERS substrate consists of an ordered Al2O3@Ag@Si nanocone array and Ag nanoparticles (Ag-NPs), both of which are fabricated individually. The Al2O3@Ag@Si nanocone array is obtained by ion-sputtering Ag on an Si nanocone array and then coating an ultrathin (∼2 nm) Al2O3 dielectric layer via atomic layer deposition (ALD). Ag-NPs are synthesized via the liquid phase method and then immersed in an organic solvent for liquid seal. For the SERS measurement, Ag-NPs are dispersed in a liquid containing the probe molecules and then, they self-assemble on the surface of the Al2O3@Ag@Si nanocones. Subsequently, the ultrathin Al2O3 dielectric layer separates Ag-NPs from the Ag@Si nanocones, forming massive gap-introduced hot spots. This substrate is sensitive to 1 pM Rhodamine R6G with an average enhancement factor of up to 109, exhibiting excellent SERS activity. Moreover, due to the protection of the Al2O3 dielectric layer and the organic solvent for the Ag@Si nanocones and Ag-NPs against oxidation, the split-type SERS substrate achieves an SERS signal with almost no attenuation after five months, indicating its good chemical stability.

中文翻译：

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Ag纳米颗粒和Al2O3 @ Ag @ Si纳米锥阵列的分体式结构：基于SERS的检测的巧妙策略。

在本文中，我们报告了一种基于分离型SERS底物的组合SERS测量的简便策略，该方法具有出色的SERS活性，检测信号的可再现性和化学稳定性。SERS衬底由有序的Al2O3 @ Ag @ Si纳米锥阵列和Ag纳米颗粒（Ag-NPs）组成，两者均是单独制造的。Al2O3 @ Ag @ Si纳米锥阵列是通过将Ag离子溅射在Si纳米锥阵列上，然后通过原子层沉积（ALD）涂覆超薄（约2 nm）的Al2O3介电层而获得的。通过液相法合成Ag-NP，然后将其浸入有机溶剂中进行液封。对于SERS测量，将Ag-NP分散在含有探针分子的液体中，然后将它们自组装在Al2O3 @ Ag @ Si纳米锥的表面上。随后，超薄的Al2O3介电层将Ag-NP与Ag @ Si纳米锥分开，形成大量由间隙引入的热点。该底物对1 pM罗丹明R6G敏感，平均增强因子高达109，表现出出色的SERS活性。此外，由于保护了Al2O3介电层以及Ag @ Si纳米锥和Ag-NPs的有机溶剂免受氧化，分体型SERS基板在五个月后几乎没有衰减，从而获得了SERS信号，表明其良好的化学性能。稳定。