Hydrated metal ions such as Na⁺, Mg²⁺, and Cu²⁺ in addition to surface species like citrate, p-mercaptobenzoic acid (PMBA), and halide anions were identified by exploiting coupled localized surface plasmons of flocculated silver nanoparticles (AgNPs). Indeed, SERS spectra provided clear evidence for the formation of citrate complexes of Co²⁺ and Cu²⁺ as well as ion pairs of metal ions and PMBA^- anions on AgNPs. For the first time, we have detected pronounced Raman bands from hydrated metal ions in flocculates of halide-covered AgNPs assigned to restricted rotation and translation at 600-200 cm^-1 and O-H stretching bands at 3500-3600 cm^-1. Interestingly, the peak frequencies of O-H stretching mode from hydrated metal ions are sensitive to metal and halide species, proving the observed water molecules are sandwiched between trapped metal ions and halide ions on adjacent AgNPs while forming a solvent shared ion pair.

通过利用絮凝的银纳米颗粒（AgNPs）耦合的局部表面等离子体激元，鉴定了除柠檬酸，对巯基苯甲酸（PMBA）和卤化物阴离子等表面物种外的水合金属离子，例如Na ⁺，Mg ²⁺和Cu ²⁺。 。事实上，SERS光谱为钴的柠檬酸盐复合物的形成提供了明确的证据²⁺和Cu ²⁺以及金属离子和PMBA的离子对^-阴离子对的AgNPs。对于第一次，我们已经检测到在分配给受限制的旋转和平移卤化物覆盖的AgNPs的絮凝水合金属离子显着的拉曼带在600-200厘米^-1和OH伸缩带在3500-3600厘米^-1。有趣的是，来自水合金属离子的OH拉伸模式的峰值频率对金属和卤化物物种敏感，证明观察到的水分子夹在相邻AgNP上的捕获金属离子和卤化物离子之间，同时形成溶剂共享的离子对。