We describe a mild, ecofriendly, and straightforward two-step strategy for making core-shell Au@Ag bimetallic nanoparticles (BMNPs) for antibacterial nanomedicine and SERS imaging. The synthesis exploits the unique properties of the cationic polymeric cyclodextrin (PolyCD) as both reducing and stabilizing agent to obtain, monodispersed and stable Au@Ag BMNPs. PolyCD-driven protocol includes the synthesis of PolyCD-coated Au monometallic nanoparticles (MNPs) as a seed material for the subsequent growing of a silver shell. PolyCD was produced by polymerization of the azido modified βCD monomers with epichlorohydrin and subsequent reduction of azido derivative. The amino groups, as hydrochloride salts (one for CD ring), are pivotal for the formation of BMNPs in mild conditions. Nanoantibiotics and SERS-nanoTag were prepared by complexation of Au@Ag BMNPs with Linezolid (Lz) and 4-mercaptophenyl boronic acid, respectively. Au@Ag@Lz complexes showed a good antibacterial activity against all tested microorganisms including the methicillin resistant Staphylococcus aureus (MRSA).

我们描述了一种温和、环保且直接的两步策略，用于制造用于抗菌纳米药物和 SERS 成像的核壳 Au@Ag 双金属纳米粒子 (BMNPs)。该合成利用阳离子聚合环糊精 (PolyCD) 作为还原剂和稳定剂的独特性质，获得了单分散且稳定的 Au@Ag BMNPs。PolyCD 驱动的协议包括合成涂有 PolyCD 的 Au 单金属纳米粒子 (MNP) 作为随后生长银壳的种子材料。PolyCD 是通过叠氮基改性的 βCD 单体与环氧氯丙烷聚合并随后还原叠氮基衍生物来制备的。氨基，作为盐酸盐（一个用于 CD 环），对于在温和条件下形成 BMNPs 至关重要。纳米抗生素和 SERS-nanoTag 分别通过 Au@Ag BMNPs 与利奈唑胺 (Lz) 和 4-巯基苯基硼酸的络合制备。Au@Ag@Lz 复合物对所有测试的微生物（包括耐甲氧西林的微生物）均显示出良好的抗菌活性金黄色葡萄球菌（MRSA）。