Sensitive and Efficient Fluorescent Fiber-Optic Sensor for In-Situ Hypoxia Detection in Solid Tumor

Accurate and timely assessment of malignant tumors in the early stage and therapy process is critical for making clear guidance and prognosis for the treatment, which can significantly elevate the cure rate of cancer patients. Fluorescent sensing and imaging of tumors have attracted extensive attention because of their advantages of high sensitivity and spatial resolution. A “plug-and-play” fluorescent fiber-optic sensor was reported for the diagnosis of tumor in our previous work. However, the route to obtain the optimization parameters and the spatial resolving capability of the tumor sensor were still elusive. In this work, we have systematically investigated the optimized design of the fiber from the aspects of structural morphology of the fiber tip, incident light intensity, and the concentration of the fluorescent probes that renders a limit-of-detection of 3 ng/mL and a response time less than 20 s. Furthermore, the sensor can reveal the hypoxic gradient of the solid tumor by virtue of its spatial sampling ability, enabling disease classification and margin identification potential. This proof-of-concept offers great opportunities for application in oncology, such as preoperative diagnosis, clinical operation guidance, and postoperative re-examination of tumors.