A possible pathogenetic factor of sickle-cell disease based on fluorescent analysis via an optofluidic resonator

Waveguide based optofluidic resonator features high precision and high sensitivity in real-time fluorescent analysis. We present a novel optofluidic resonator following the hollow-core metal-cladding waveguide structure, which is then used to record the real-time binding process of Fe(2+) and Fe(3+) with protoporphyrin IX (PpIX) in PBS solution, respectively. The central fluorescent wavelength of compound with Fe(2+) is in good accordance with that of the normal hemoglobin, whilst the peaks of the Fe(3+) compound match the hemoglobin specimen from sickle-cell disease (SCD) patients. Similar statement holds when we monitor the real-time oxidation processes of these products by injecting oxygen into the optofluidic chip. These observations lead to the speculation that the SCD is caused by replacing the Fe(2+) in hemoglobin with Fe(3+), which may be insightful in the discovery of new clinical routes to cure this disease.