Highly sensitive reduced graphene oxide microelectrode array sensor

• We show a process to fabricate microelectrode array sensors for thin active layers.
• Process is used to fabricate reduced graphene oxide sensor on flexible plastic.
• The sensor displayed high sensitivities towards dopamine.
• The sensor performance was investigated in highly resistive media.
• The sensor was integrated into a microfluidic system.

Reduced graphene oxide (rGO) has been fabricated into a microelectrode array (MEA) using a modified nanoimprint lithography (NIL) technique. Through a modified NIL process, the rGO MEA was fabricated by a self-alignment of conducting Indium Tin Oxide (ITO) and rGO layer without etching of the rGO layer. The rGO MEA consists of an array of 10 μm circular disks and microelectrode signature has been found at a pitch spacing of 60 μm. The rGO MEA shows a sensitivity of 1.91 nA μm−1 to dopamine (DA) without the use of mediators or functionalization of the reduced graphene oxide (rGO) active layer. The performance of rGO MEA remains stable when tested under highly resistive media using a continuous flow set up, as well as when subjecting it to mechanical stress. The successful demonstration of NIL for fabricating rGO microelectrodes on flexible substrate presents a route for the large scale fabrication of highly sensitive, flexible and thin biosensing platform.