A novel waveguide based optofluidic fluorescent resonator was applied to monitor the real-time binding process of Fe2+ and Fe3+ with protoporphyrin IX (PpIX) in PBS solution, respectively. Then, oxygen is dissolved in the PBS solution to react with these two products and their fluorescent spectra are also recorded by the optofluidic chip. Compared with the hemoglobin, we found that the central fluorescent wavelength of compound with ferrous ion are in good accordance with the normal hemoglobin, whilst the Fe3+ compound matches the hemoglobin specimen from sickle-cell disease. Thus we are led to infer that the anoxia of sickle-cell disease is caused by replacing the Fe2+ in hemoglobin with Fe3+. This conclusion may be insightful in the discovery of new clinical routes to cure the sickle-cell disease.

Hailang Dai, ChengYin, XiaonaYe, Bei Jiang, Maowu Ran, Zhuangqi Cao1 &Xianfeng Chen，A possible pathogenetic factor of sickle-cell disease based on fluorescent analysis via an optofluidic resonator. Scientific Reports 7: 3174 | DOI:10.1038/s41598-017-03634-8.