Effect of protein adsorption on electrospun hemoglobin/gelatin-MWCNTs microbelts modified electrode: Toward electrochemical measurement of hydrogen peroxide

Abstract

The on-line electrochemical analysis is one of powerful strategies in analytical chemistry and pathophysiology. To achieve high sensitivity and long-term stability of electrochemical biosensor, the bottleneck challenge is the spontaneous proteins adsorption onto the electrode surface within the biological fluids or in vivo environments. In this work, a hemoglobin/gelatin-multiwalled carbon nanotubes microbelts modified electrode (Hb/gelatin-MWCNTs/GC electrode) was successfully fabricated via one-step electrospinning process. The results of atomic force microscopy (AFM), scanning electron microscopy (SEM) and water contact angle test confirmed the electrospun Hb/gelatin-MWCNTs microbelts possessed smooth and hydrophilic surfaces. Furthermore, the electrospun Hb/gelatin-MWCNTs/GC electrode after protein adsorption displayed an excellent electrocatalytic sensitivity toward the reduction of hydrogen peroxide (H2O2). Moreover, the Hb/gelatin-MWCNTs/GC electrode presented very high biological affinity to H2O2 (Kmapp=503.4 ± 2.8 μmol L−1) after 360 min protein adsorption compared to that of the electrode before protein adsorption (Kmapp=298.1 ± 3.1 μmol L−1). The microbelts constructed H2O2 biosensor showed high selectivity, stability and reproducibility after protein adsorption. Therefore, this work provided the proof of the concept that the electrospun Hb/gelatin-MWCNTs/GC electrode displayed excellent sensing performance to H2O2 after protein adsorption, which could enable the implantable electrochemical biosensor for the on-line analysis.