Facile patterning of reduced graphene oxide film into microelectrode array for highly sensitive sensing

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Microelectrode arrays (MEAs) are crucial for sensitive electrochemical detection.
• Graphene-based materials offer unique electronic properties for electrode fabrication.
• Existing methods for fabricating graphene MEAs can be complex and costly.

Purpose of the Study:

• To develop a novel, low-cost technique for fabricating reduced graphene oxide (rGO)-based microelectrode arrays (MEAs).
• To demonstrate the electroanalytical capabilities of the fabricated rGO MEAs for sensitive detection applications.

Main Methods:

• Fabrication of a polydimethylsiloxane (PDMS) mold with microwells using soft lithography.
• Layer-by-layer assembly of graphene oxide (GO) onto indium tin oxide (ITO) electrodes.
• Selective reduction of GO to rGO using a hydrazine-infused PDMS mold for patterning.
• Characterization using Kelvin probe force microscopy (KFM), atomic force microscopy (AFM), and cyclic voltammetry (CV).
• Electrodeposition of Prussian blue (PB) onto rGO MEAs for enhanced detection.

Main Results:

• Successfully fabricated patterned rGO microelectrodes with a diameter of approximately 3 μm.
• rGO electrodes exhibited characteristic microelectrode array (MEA) behavior with microampere current responses.
• The Prussian blue/rGO-based MEA demonstrated a lower detection limit and higher current density for H2O2 detection compared to macroscopic rGO electrodes.

Conclusions:

• The developed soft lithography technique provides a simple and cost-effective strategy for fabricating graphene-based MEAs.
• The rGO MEAs show significant potential for sensitive electroanalytical applications.
• This method facilitates the development of advanced electrochemical sensors.