ACS Sens. 2018 Aug 24;3(8):1499-1509. doi: 10.1021/acssensors.8b00287. Epub 2018 Aug 14.
Microbial biofilms possess intrinsic resistance against conventional antibiotics and cleaning procedures; thus, a better understanding of their complex biological structures is crucial in both medical and industrial applications. Existing laboratory methodologies have focused on macroscopic and mostly indirect characterization of mechanical and microbiological properties of biofilms adhered on a given substrate. However, the kinetics underlying the biofilm formation is not well understood, while such information is critical to understanding how drugs and chemicals influence the biofilm formation. Herein, we report the use of localized surface plasmon resonance (LSPR) for real-time, label-free monitoring of E. coli biofilm assembly on a nanoplasmonic substrate consisting of gold mushroom-like structures. Our LSPR sensor is able to capture the signatures of biofilm formation in real-time by measuring the wavelength shift in the LSPR resonance peak with high temporal resolution. We employ this sensor feature to elucidate how biofilm formation is affected by different drugs, including conventional antibiotics (kanamycin and ampicillin) as well as rifapentine, a molecule preventing cell adhesion yet barely affecting bacterial viability and vitality. Due to its flexibility and simplicity, our LSPR based platform can be used on a wide variety of clinically relevant bacteria, thus representing a valuable tool in biofilm characterization and drug screening.
微生物生物膜对常规抗生素和清洁程序具有内在抗性；因此，更好地了解其复杂的生物结构对于医学和工业应用都至关重要。现有的实验室方法侧重于对生物膜在给定基底上的机械和微生物特性进行宏观和大多是间接的表征。然而，生物膜形成的动力学尚未得到很好的理解，而这些信息对于了解药物和化学物质如何影响生物膜的形成至关重要。在此，我们报告了使用局部表面等离子体共振（LSPR）实时、无标记监测由金蘑菇状结构组成的纳米等离子体基底上大肠杆菌生物膜组装的方法。我们的 LSPR 传感器能够通过以高时间分辨率测量 LSPR 共振峰的波长移动来实时捕获生物膜形成的特征。我们利用该传感器功能来阐明生物膜形成如何受到不同药物的影响，包括常规抗生素（卡那霉素和氨苄西林）以及利福平，后者是一种阻止细胞黏附但几乎不影响细菌活力和生命力的分子。由于其灵活性和简单性，我们基于 LSPR 的平台可用于多种临床相关细菌，因此它是生物膜表征和药物筛选的有价值工具。
