  The ability to form diamond electrodes on insulating polycrystalline diamond
substrates using single-step laser patterning, and the use of the electrodes as
a substrate that supports the adhesion and proliferation of human mesenchymal
stem cells (hMSCs) is demonstrated. Laser induced graphitisation results in a
conductive amorphous carbon surface, rich in oxygen and nitrogen terminations.
This results in an electrode with a high specific capacitance of 182 uF/cm2, a
wide water window of 3.25 V, and a low electrochemical impedance of 129
Ohms/cm2 at 1 kHz. The electrodes surface exhibited a good level of
biocompatibility with hMSCs, supporting cell adhesion and proliferation. The
cells cultured on the electrode displayed significant elongation and alignment
along the direction of the laser patterned microgrooves. Because of its
favourable electrochemical performance and biocompatibility, the
laser-patterned diamond electrodes create a potential for a versatile platform
in stem cell therapeutics.
