College of Chemistry and Materials Science, Jinan University, Guangzhou, Guangdong 510632, China.
College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, China.
Anal Chem. 2022 Apr 19;94(15):5785-5796. doi: 10.1021/acs.analchem.1c04920. Epub 2022 Mar 28.
New strategies combining sensitive pathogenic bacterial detection and high antimicrobial efficacy are urgently desirable. Here, we report smart triple-functional Au-Ag-stuffed nanopancakes (AAS-NPs) exhibiting (1) controllably oxidative Ag-etching thickness for simultaneously obtaining the best surface-enhanced Raman scattering (SERS) enhancement and high Ag-loading antibacterial drug delivery, (2) expressive Ag-accelerated releasing capability under neutral phosphate-buffered saline (PBS) (pH ∼ 7.4) stimulus and robust antibacterial effectiveness involving sustainable Ag release, and (3) three-in-one features combining specific discrimination, sensitive detection, and inactivation of different pathogenic bacteria. Originally, AAS-NPs were synthesized by particle growth of the selective Ag-etched Au@Ag nanoparticles with K[Fe(CN)], followed by the formation of an unstable Prussian blue analogue for specifically binding with bacteria through the cyano group. Using specific bacterial "fingerprints" resulting from the introduction of dual-function 4-mercaptophenylboronic acid (4-MPBA, serving as both the SERS tag and internal standard) and a SERS sandwich nanostructure that was made of bacteria/SERS tags/AAS-NPs, three bacteria (, , and ) were highly sensitively discriminated and detected, with a limit of detection of 7 CFU mL. Meanwhile, AAS-NPs killed 99% of 1 × 10 CFU mL bacteria within 60 min under PBS (pH ∼ 7.4) pretreatment. Antibacterial activities of PBS-stimulated AAS-NPs against , and were extraordinarily increased by 64-fold, 72-fold, and 72-fold versus PBS-untreated AAS-NPs, respectively. The multiple functions of PBS-stimulated AAS-NPs were validated by bacterial sensing, inactivation in human blood samples, and bacterial biofilm disruption. Our work exhibits an effective strategy for simultaneous bacterial sensing and inactivation.
新的策略需要结合灵敏的致病细菌检测和高抗菌功效。在这里，我们报告了智能三重功能的 Au-Ag 填充纳米饼（AAS-NPs），其具有（1）可控的氧化 Ag 刻蚀厚度，同时获得最佳的表面增强拉曼散射（SERS）增强和高 Ag 负载抗菌药物输送，（2）在中性磷酸盐缓冲盐水（PBS）（pH ∼ 7.4）刺激下表达 Ag 加速释放能力和强大的抗菌效果，包括持续的 Ag 释放，以及（3）三种功能结合，包括特异性鉴别、灵敏检测和不同致病菌的失活。最初，AAS-NPs 通过选择性 Ag 刻蚀的 Au@Ag 纳米粒子与 K[Fe(CN)6]的粒子生长合成，然后形成不稳定的普鲁士蓝类似物，通过氰基与细菌特异性结合。利用通过双功能 4-巯基苯硼酸（4-MPBA，既作为 SERS 标记物又作为内标）引入的特异性细菌“指纹”和由细菌/SERS 标记物/AAS-NPs 组成的 SERS 夹心纳米结构，高度灵敏地鉴别和检测了三种细菌（、和），检测限为 7 CFU mL。同时，AAS-NPs 在 PBS（pH ∼ 7.4）预处理下 60 分钟内杀死了 1×10 CFU mL 的 99%细菌。与未经 PBS 处理的 AAS-NPs 相比，PBS 刺激的 AAS-NPs 对、和的抗菌活性分别增加了 64 倍、72 倍和 72 倍。PBS 刺激的 AAS-NPs 的多种功能通过细菌感应、在人血样本中的失活以及细菌生物膜破坏得到验证。我们的工作展示了一种同时进行细菌感应和失活的有效策略。
