Abstract
Background: Graphite pencil drawn on paper electrode (PDP) is one of the low cost electrodes due to the good conductivity. Prussian blue (PB) has been widely used in sensors due to its high electrocatalytic activity toward H2O2 reduction at relatively low potential avoiding the interferences of other biological species. The major drawback of PB is their relatively low operational stability since hydroxyl ions causes the collapse of Fe-CN-Fe of PB bonds. Interestingly, a combination of magnetic nanoparticles, Fe3O4 with PB would not only enhance Fe3O4 properties, but also improves the operational stability of PB. In this work, a disposable PDP modified with Fe3O4-PB as sensor was successfully fabricated.
Methods: To prepare PDP, lead pencil 4B and Whatman filter paper were used. Briefly, Whatman filter paper was cut into small slides then by hand abrasion of the pencil on the paper surface. Melted candle was used to cover part of the electrode to adjust the working electrode zone. Fe3O4 was prepared by the hydrothermal technique. Transmission electron microscope, scanning electron microscopy, X-ray diffraction, Contact angle (OCA 15 plus) and electrochemical workstation (CHI660e) were used to characterize both PDP and Fe3O4-PB nanoparticles.
Results: The PDP possessed excellent electrochemical properties and good reproducibility. Furthermore, the Fe3O4-PB / PDP electrode was quite stable even in neutral and lower alkaline solutions with good electro-catalysis.
Conclusion: Both Fe3O4-PB nanoparticles and PDP can be considered as promising candidate materials for fabricating electrochemical sensors, especially in the resource limited condition.
Keywords: Magnetite Prussian blue core-shell nanocomposite, graphite pencil drawn electrode on paper, electrochemical sensor, electrochemical properties, cyclic voltammetry, transmission electron microscope (TEM).
Graphical Abstract
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