Micro-/nanofibers (MNFs) are optical fibers with diameters close to or below the wavelength of the guided light. These tiny fibers can offer engineerable waveguiding properties including optical confinement, fractional evanescent fields, and surface intensity, which is very attractive to optical sensing on the micro-/nano scale. In this review, we first introduce the basics of MNF optics and MNF optical sensors from physical and chemical to biological applications and review the progress and current status of this field. Then, we review and discuss hybrid MNF structures for advanced optical sensing by merging MNFs with functional structures including chemical indicators, quantum dots, dye molecules, plasmonic nanoparticles, 2-D materials, and optofluidic chips. Thirdly, we introduce the emerging trends in developing MNF-based advanced sensing technology for ultrasensitive, active, and wearable sensors and discuss the future prospects and challenges in this exciting research field. Finally, we end the review with a brief conclusion.

微纤维/纳米纤维（MNF）是直径接近或低于引导光波长的光纤。这些微小的纤维可以提供可工程化的波导性能，包括光学限制，分数渐逝场和表面强度，这对于微米/纳米级的光学传感非常有吸引力。在这篇综述中，我们首先介绍了从物理和化学到生物应用的MNF光学和MNF光学传感器的基础知识，并回顾了该领域的进展和现状。然后，我们将通过合并MNF与功能结构（包括化学指示剂，量子点，染料分子，等离激元纳米颗粒，2-D材料和光流体芯片）来审查和讨论用于高级光学传感的混合MNF结构。第三，我们介绍了开发用于超灵敏，有源和可穿戴传感器的基于MNF的先进传感技术的新兴趋势，并讨论了这一激动人心的研究领域的未来前景和挑战。最后，我们以简短的结论结束了本次审查。