Surface-enhanced Raman spectroscopy (SERS) is a powerful technique that has found applications in many research fields. As promising alternatives to the current most popular plasmonic metal SERS substrates, semiconductor SERS substrates have many appealing attributes. However, they permit signal enhancement only to analytes adsorbed chemically on their surface, which means that semiconductor-based SERS can only be used for studying model analytes such as dyes or thiols. Using volatile organic compounds (VOCs) as an example, we demonstrate for the first time the detection of non-adsorbing analytes on ZnO nanoparticles. Specifically, this was achieved by coating ZnO nanoparticles with ZIF-8 shells, which enriches VOC molecules and dampens the decay of the electromagnetic field around their surface, thereby significantly boosting their electromagnetic enhancing capability such that it permits signal enhancement for non-adsorbing analytes. Importantly, the MOF-coating strategy is universal, which means that it may enable the detection of a wider variety of non-adsorbing analytes where conventional semiconductor-based SERS fails.

表面增强拉曼光谱 (SERS) 是一种强大的技术，已在许多研究领域得到应用。作为当前最流行的等离子体金属 SERS 基板的有前途的替代品，半导体 SERS 基板具有许多吸引人的特性。然而，它们只允许对化学吸附在其表面的分析物进行信号增强，这意味着基于半导体的 SERS 只能用于研究模型分析物，例如染料或硫醇。以挥发性有机化合物 (VOC) 为例，我们首次展示了 ZnO纳米粒子上非吸附性分析物的检测。具体来说，这是通过用 ZIF-8 壳包覆 ZnO 纳米粒子来实现的，它可以丰富 VOC 分子并抑制 ZnO 纳米粒子的衰变它们表面周围的电磁场，从而显着提高它们的电磁增强能力，从而允许非吸附分析物的信号增强。重要的是，MOF 涂层策略是通用的，这意味着它可以检测更广泛的非吸附分析物，而传统的基于半导体的 SERS 则失败了。