An Electrochemical Biosensor Based on Gold Nanoparticles/Carbon Nanotubes Hybrid for Determination of recombinant human erythropoietin in human blood plasma

Abstract

The aim of this study is to fabricate an electrochemical biosensor using a decreased recombinant human erythropoietin (rhuEPO)/Au NPs/CNTs nanohybrid modified glassy carbon electrode (GCE) to measure the amount of the peptide hormone rhuEPO in a sample of cyclists' blood plasma. The GCE surface was modified with an Au NPs/CNTs nanohybrid structure using the electrodeposition method, and rhuEPO was reduced on the nanohybrid structure using chronoamperometry. Studies on the structural properties of electrodeposited Au NPs/CNTs revealed that these particles had a suitable distribution on the surface of the CNTs and could be regarded as a hybrid nanoparticle nano-disperse ensemble. The development of decorated Au NPs on CNTs porous structure surface facilitated the functionalization of the nanoparticles with rhuEPO specific antibody as well as promoted the stability of rhuEPO biosensors, and reduced rhuEPO promoted the selectivity of biosensors, according to electrochemical analyses of rhuEPO biosensors by DPV and amperometry. According to amperometric experiments, the linear range was 0 to 22000 ng/l, and a sensitivity value of 4.3907 μA/μgl-1 for reduced rhuEPO/Au NPs/CNTs/GCE toward rhuEPO was achieved. The detection threshold was set at 1 ng/l as well. These results demonstrated the wide linear range and adequate detection limit value of the decreased rhuEPO/Au NPs/CNTs nanohybrid when compared to recently reported rhuEPO sensors and biosensors. rhuEPO was extracted using magnetic beads and reduced on Au NPs/CNTs/GCE, and the results showed excellent agreement and validity between amperometry and ELISA analyses. The applicability and validity of reduced rhuEPO/Au NPs/CNTs/GCE were investigated for the determination level of rhuEPO in a blood plasma sample from cyclists. Additionally, the developed approach can be used to determine the level of rhuEPO in clinical samples because of the appropriate relative standard deviation (≥4.69 %) and relative recovery (≥99.00 %) values.