An electrochemical immune bioassay for naphthalene using Prussian blue and a nano-gold particle modified glass carbon electrode

Abstract

A sensitive amperometric immunosensor for the fast detection of naphthalene is developed using a layer-by-layer assembly method. Prussian blue was first electrodeposited onto a glass carbon electrode as an electron mediator. Afterwards a nano-gold layer was formed on the Prussian blue film by electrochemical reduction of HAuCl₄ solution. Finally, anti-naphthalene was adsorbed onto the nano-gold film to construct a sensitive immunosensor. The characteristics of the modified electrode at different stages of preparation were studied by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimal experimental conditions, the current response of the immunosensor was inversely proportional to the concentration of naphthalene in the range of 4.0 to 100 ng mL⁻¹ with a detection limit of 0.06 ng mL⁻¹ (S/N = 3). This method was applied to the naphthalene detection in river water with satisfactory results.