Disposable electrochemical sensors for hemoglobin detection based on ferrocenoyl cysteine conjugates modified electrode

The abnormal content of hemoglobin in human body can lead to several diseases such as anemia, thalassemia, leukemia, heart disease. Therefore, it is very important for sensitive detection of hemoglobin in clinical analysis. An electrochemical approach is presented for detecting hemoglobin using disposable electrochemical sensors, which were based on the ability of the redox active ferrocene group of Fc[CO-Cys(Trt)-OMe]2 and Fc[CO-Glu-Cys-Gly-OH]. The two electroactive materials were adsorbed onto gold nanoparticles that were previously electrochemically deposited onto screen-printed electrodes. The as-prepared sensors were characterized by scanning electron microscopy and energy dispersive spectroscopy, and their electrochemical properties were characterized by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Results indicated the Fc[CO-Glu-Cys-Gly-OH] prepared sensor showed enhanced current responses for hemoglobin catalysis than the Fc[CO-Cys(Trt)-OMe]2 prepared sensor. Optimal operating conditions were determined for hemoglobin detection by differential pulse voltammetry. The concentration of hemoglobin showed a good linear relationship with the current difference in the range of 0.1–1000 μg/mL and with 0.03 μg/mL limit of detection. The development of this electrochemical sensor was used for hemoglobin detection in human serum with a R.S.D. lower than 4.7% and recovery between 95.5% and 103.2%, which was in agreement with the data obtained from typical clinical analysis.