Amperometric biosensor for nitrite and hydrogen peroxide based on hemoglobin immobilized on gold nanoparticles/polythionine/platinum nanoparticles modified glassy carbon electrode

摘要

This paper describes a convenient and effective strategy to construct a highly sensitive amperometric biosensor for nitrite (NO _2 -) and hydrogen peroxide (H _2O _2). First, Pt nanoparticles (PtNPs) were electrodeposited on a glassy carbon electrode (GCE) surface, which promoted electron transfer and enhanced the loading of poly-thionine (PTH). Subsequently, thionine (TH) was electropolymerized on the PtNPs/GCE, and gold nanoparticles (AuNPs) were assembled onto the PTH film to improve the absorption capacity of hemoglobin (Hb) and further facilitate electron transfer. Finally, Hb was immobilized onto the electrode through the AuNPs. Results: Cyclic voltammetry (CV) and scanning electron microscopy (SEM) were used to characterize the fabrication process of the sensing surface. Under optimum conditions, the biosensors can be used for the determination of NO _2 - in the concentration range 70 nmol L ~(-1) to 1.2 mmo L ~(-1) and of H _2O _2 in the range 4.9 μmol L ~(-1) to 6.8 mmol L ~(-1). The detection limits (S/N = 3) were 20 nmol L ~(-1) and 1.4 μmol L ~(-1), respectively. CONCLUSION: The biosensor exhibits good analytical performance, acceptable stability and good selectivity.