Biomarkers with ultralow concentration in the actual samples play a vital role in the clinical disease diagnosis, infectious disease screening, food security, and environmental monitoring. Fiber optic (FO)-based surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR) biosensors attract immense attention for , and rapid detection due to their merits of miniaturized devices, easy integration, and low cost, showing great promising for point of care point-of-caring test. In order to achieve ultrasensitive detection of biomarkers, great effort focused on design of a sensitive FO-based biosensor on the aspect of novel FO probes and signal amplification strategies. Firstly, novel FO probes, including gating and new structure-based, were develop to adjust the light propagation and allow intensely interaction between the light and metal film or nanoparticles, which excites strong SPR or LSPR for sensitive biosensor. Then, nanomaterials on FO surface improved the intensity of electromagnetic fields or provided a good scaffold to modify with more recognition element for signal amplification. Nucleic acid circuits get rid of the limitation of the signal-to-target ratio of 1:1 and exhibited high efficiency to amplify the signal. These efforts have also led to the application of FO-SPR and LSPR sensors for detection of various targets, such as cells, nucleic acids, proteins, and small molecules. In the review, we summarized the important progress of the ultrasensitive FO-based biosensor about emerging FO probes and signal amplification strategies, also discussed its opportunities and challenges for the point-of-caring test. The review aims to promote the application of the FO-SPR and LSPR from experiments to real samples.

中文翻译：

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使用新颖结构和新兴信号放大策略的基于光纤 SPR/LSPR 的超灵敏生物传感器的最新进展

实际样品中超低浓度的生物标志物在临床疾病诊断、传染病筛查、食品安全、环境监测等方面发挥着至关重要的作用。基于光纤（FO）的表面等离子共振（SPR）和局域表面等离子共振（LSPR）生物传感器因其器件小型化、易于集成、成本低廉等优点而受到广泛关注，并在快速检测方面展现出巨大的应用前景。护理点护理测试。为了实现生物标志物的超灵敏检测，人们在新型FO探针和信号放大策略方面致力于设计灵敏的基于FO的生物传感器。首先，开发了新型FO探针，包括门控探针和基于新结构的探针，以调节光传播并允许光与金属膜或纳米颗粒之间发生强烈相互作用，从而激发强SPR或LSPR以用于敏感的生物传感器。然后，FO表面的纳米材料可以提高电磁场的强度，或者提供良好的支架来修饰更多的识别元件以放大信号。核酸电路摆脱了信号与靶标比例1:1的限制，表现出高效率的信号放大能力。这些努力还导致了 FO-SPR 和 LSPR 传感器应用于检测各种目标，如细胞、核酸、蛋白质和小分子。在这篇综述中，我们总结了基于 FO 的超灵敏生物传感器在新兴 FO 探针和信号放大策略方面的重要进展，并讨论了其在护理点测试中的机遇和挑战。该综述旨在促进FO-SPR和LSPR从实验到实际样品的应用。