A simple and reusable fluorescent sensor for heme proteins based on a conjugated polymer-doped electrospun nanofibrous membrane

We reported a simple and reusable fluorescent sensor for heme proteins based on the electrospun nanofibrous membrane doped with a fluorescent conjugated polymer P. The sensor showed favorable fluorescence sensing performance towards the heme proteins, including hemoglobin (Hb), myoglobin (Mb) and cytochrome c (Cyt c). The surface wettability and sensing performance of the electrospun nanofibrous membrane were investigated in detail using Hb as the model. The nanofibrous sensor showed satisfactory reversibility with less than 10% signal loss after nine quenching–regeneration cycles, and good batch-to-batch reproducibility with a relative standard deviation of 3.4% (n = 3). The linear range of the sensor for Hb determination was 2.0 × 10−8 to 3.0 × 10−6 M with a detection limit of 1.2 × 10−8 M. The quenching process is mainly based on the fluorescence resonance energy transfer mechanism between the fluorescent conjugated polymer P and the heme prosthetic groups, therefore the sensor was selective against most of the common interferents. As an example to evaluate the feasibility of the sensor in practical application, Hb in human blood samples was determined and the results were in good agreement with the data provided by the hospital. To the best of our knowledge, this is the first work using fluorescent electrospun nanofibrous sensor for protein analysis in real biological sample.