We present a facile and effective method for fabrication of the localized surface plasmon resonance (LSPR) optical fiber sensor assisted by two polydopamine (PDA) layers with enhanced plasmonic sensing performance. The first PDA layer was self-polymerized onto the bare optical fiber to provide the catechol groups for the reduction from Ag⁺ to Ag^o through chelating and redox activity. As the reduction of Ag⁺ proceeds, Ag nanoparticles (NPs) were grown in-situ on the PDA layer with uniform distribution. The second PDA layer was applied to prevent Ag NPs from oxidating and achieve an improvement of LSPR signal. The PDA/Ag/PDA-based optical fiber sensor has an enhanced LSPR sensitivity of 961 nm/RIU and excellent oxidation resistance. The stable PDA/Ag/PDA-based LSPR sensor with high optical performance is very promising for future application in optical sensing field.

中文翻译：

---

聚多巴胺辅助在光纤上稳定银纳米颗粒的制备，以增强等离子体感测。

我们提出了一种简便有效的方法来制造由两个具有增强的等离子体感应性能的聚多巴胺（PDA）层辅助的局部表面等离子体共振（LSPR）光纤传感器。将第一个PDA层自聚合到裸光纤上，以提供儿茶酚基团，以通过螯合和氧化还原活性将其从Ag ⁺还原为Ag ^o。由于Ag ⁺的还原随后，Ag纳米颗粒（NPs）在PDA层上以均匀分布原位生长。施加第二个PDA层以防止Ag NP氧化并改善LSPR信号。基于PDA / Ag / PDA的光纤传感器具有961 nm / RIU的增强LSPR灵敏度和出色的抗氧化性。具有高光学性能的基于PDA / Ag / PDA的稳定LSPR传感器对于光传感领域的未来应用非常有希望。