West China School of Public Health, Sichuan University, Chengdu, China.
West China School of Public Health, Sichuan University, Chengdu, China; Chengdu Center for Disease Control and Prevention, Chengdu, China.
Biosens Bioelectron. 2018 Oct 15;117:347-353. doi: 10.1016/j.bios.2018.06.005. Epub 2018 Jun 5.
A fiber optic surface plasmon resonance (FOSPR) sensor was developed for detection of Escherichia coli O157:H7 (E. coli O157:H7) in water and juice, based on antimicrobial peptides (AMP), Magainin I, as recognition elements and silver nanoparticles-reduced graphene oxide (AgNPs-rGO) nanocomposites assisted signal amplification. The uniform AgNPs-rGO was fixed on the surface of optical fiber and covered with gold film. Not only was the SPR response greatly enhanced, but also the AgNPs was prevented from being oxidized. The FOSPR showed a sensitivity of about 1.5 times higher than that fabricated only with gold film. In the assay, Magainin I, immobilized on the surface of gold film, could specifically capture E. coli O157:H7, resulting in the wavelength shift of the SPR absorption peak. Under the optimized conditions, the SPR resonance wavelength exhibited a good linear relationship with natural logarithm of the target bacteria concentration in the range of 1.0 × 10 to 5.0 × 10 cfu/mL with the detection limit of 5.0 × 10 cfu/mL (S/N = 3). The FOSPR sensor showed good specificity for E. coli O157:H7 detection compared to other bacteria similar to the target bacterial species. Furthermore, the FOSPR sensor was successfully applied to the detection of E. coli O157:H7 in water, fruit and vegetable juice with the satisfactory recoveries of 88-110%. This assay for E. coli O157:H7 detection possesses high sensitivity, good selectivity, reproducibility and stability. In addition, the AMP based SPR biosensing methodology could be extended to detect a wide variety of foodborne pathogens. Therefore, the versatile method might become a potential alternative tool in food analysis and early clinical diagnosis.
一种光纤表面等离子体共振（FOSPR）传感器，基于抗菌肽（AMP）、Magainin I 作为识别元件，以及银纳米粒子-还原氧化石墨烯（AgNPs-rGO）纳米复合材料辅助信号放大，用于检测水中和果汁中的大肠杆菌 O157:H7（E. coli O157:H7）。均匀的 AgNPs-rGO 固定在光纤表面，并覆盖金膜。这不仅极大地增强了 SPR 响应，还防止了 AgNPs 被氧化。与仅使用金膜制备的传感器相比，该 FOSPR 的灵敏度提高了约 1.5 倍。在该测定中，固定在金膜表面的 Magainin I 可以特异性地捕获大肠杆菌 O157:H7，导致 SPR 吸收峰的波长发生位移。在优化条件下，SPR 共振波长与目标细菌浓度的自然对数在 1.0×10 至 5.0×10 cfu/mL 范围内呈现良好的线性关系，检测限为 5.0×10 cfu/mL（S/N=3）。与目标细菌种类相似的其他细菌相比，FOSPR 传感器对大肠杆菌 O157:H7 的检测具有良好的特异性。此外，该 FOSPR 传感器成功应用于水、水果和蔬菜汁中大肠杆菌 O157:H7 的检测，回收率为 88-110%。该大肠杆菌 O157:H7 检测方法具有灵敏度高、选择性好、重现性和稳定性好等优点。此外，基于 AMP 的 SPR 生物传感方法可以扩展到检测各种食源性病原体。因此，这种多功能方法可能成为食品分析和早期临床诊断的潜在替代工具。
