Patterning of graphene with tunable size and shape for microelectrode array devices

Large size and high quality graphene grown by chemical vapour deposition (CVD) has been fabricated into an array of discrete graphene sheets with well-defined sizes and shapes. A fabrication process based on nanoimprint lithography has been developed to achieve shape tunability with sizes ranging from micrometer to nanometer. The technique preserves the quality of the CVD grown graphene and offers the versatility of transferring the graphene array onto any rigid or flexible substrate. The process is then expanded to fabricating a graphene based microelectrode array whose performance is demonstrated in the real time sensing of peroxidase excreted by breast cancer cells. The device displayed a linear working range of 0.01–25 mM and a sensitivity of 8.8 mA mol−1.