Cancer is one of the most common diseases to threaten human health. If individuals with malignant tumors are screened via a single cell, medical workers are greatly advantageous to early diagnosis and intervention in malignant tumors therapy. In this letter, we propose a fluorescence detection map to rapidly distinguish whether the chromosomes of cell are normal or abnormal by detection of fluorescent intensity of single cell. Herein, we draw a map from single cell with an abnormal number of chromosomes is monitored in real time. Moreover, this way offers precise and prompt detection of the surviving of cancer cells at or near the site of the tumor after treatments for cancer, which can achieve personalized cancer diagnosis and therapy. Therefore, cancer recurrences and metastasis can be effectively identified, utilizing this ultrasensitive detection method of abnormal chromosome number.

In this paper, we provide fluorescence detection map drawing by strong coupling waveguide, hollow-core metal-cladding optofluidic waveguide, to detect the intensity of fluorescence from a single cell and analyze the chromosome number in the cell. Our strategy is described as follows: Firstly, cells with DAPI-stained chromosomes are injected into a sample channel one by one. Meanwhile, the specific ultrahigh order modes (UOM) in the guiding layer of waveguide are excited by adjusting the incident angle of light to fulfill the phase match condition. Secondly, when cells are injected into the channel, the intensity of fluorescence is significantly changed and monitored. Fluorescent faculae are found in the coupled area of the light spot and the fluorescence intensity of chromosomes can be measured at a fixed angle.

Fig. 1. The experimental results show that the mouse’s chromosome number changes in the sperm cells.

Finally, the leaked fluorescence of single cell through the coupling layer is collected and recorded. The fluorescence intensity is proportional to the number of chromosomes. By analyzing the intensity of leaked fluorescence, we can draw a map to distinguish the number of the chromosomes from single cell and detect whether it is normal or not. In this way, we precisely and promptly detect the reproductive cells of male mice, lung cancer cell, and surviving of cancer cells after treatment of cancer by the three categories of therapy.

Fig. 2. Application of the fluorescence detection map with personalized cancer treatment to optimize therapeutic results.

课题组通过连续实验已经精心的设计，通过实验结果可以判断，利用我们的检测技术可以有效的控制癌症的复发，并且在治疗过程中实时检测癌症细胞，判断癌细胞是否完全清除，对癌症的治疗起到很有用的关键作用。

The research was published in “Hailang Dai†, Hongrui Shan†, Zhangchi Sun†, Daopeng Dai, Yuxi Shang, Zhuangqi Cao, and Xianfeng Chen*, Single-cell detection by enhancement of fluorescence in waveguides for cancer diagnosis and therapy, Photonics Research, 9(12), 2381-2387 (2021)”.

Link: https://doi.org/10.1364/PRJ.435686