Development and characterization of a diamond-insulated graphitic multi electrode array realized with ion beam lithography

Abstract

The detection of quantal exocytic events from neurons and neuroendocrine cells is a challenging task in neuroscience. One of the most promising platforms for the development of a new generation of biosensors is diamond, due to its biocompatibility, transparency and chemical inertness. Moreover, the electrical properties of diamond can be turned from a perfect insulator into a conductive material (resistivity Ohm cm) by exploiting the metastable nature of this allotropic form of carbon. A 16 channels MEA (Multi Electrode Array) suitable for cell culture growing has been fabricated by means of ion implantation. A focused 1.2 MeV He+ beam was scanned on a IIa single-crystal diamond sample (4.5x4.5x0.5 mm3) to cause highly damaged sub-superficial structures that were defined with micrometric spatial resolution. After implantation, the sample was annealed. This process provides the conversion of the sub-superficial highly damaged regions to a graphitic phase embedded in a highly insulating diamond matrix. Thanks to a three-dimensional masking technique, the endpoints of the sub-superficial channels emerge in contact with the sample surface, therefore being available as sensing electrodes. Cyclic voltammetry and amperometry measurements of solutions with increasing concentrations of adrenaline were performed to characterize the biosensor sensitivity. The reported results demonstrate that this new type of biosensor is suitable for in vitro detection of catecholamine release.

14 pages, 5 figures

References in corpus (8)

• Evidence of light guiding in ion-implanted diamond
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• Finite element analysis of ion-implanted diamond surface swelling
• Modification of the structure of diamond with MeV ion implantation
• Controlled variation of the refractive index in ion-damaged diamond
• Spectroscopic measurement of the refractive index of ion-implanted diamond
• Complex refractive index variation in proton-damaged diamond
• Direct fabrication and IV characterization of sub-surface conductive channels in diamond with MeV ion implantation

Cited by in corpus (3)

• Microelectrode arrays of diamond-insulated graphitic channels for real time detection of exocytotic events from cultured chromaffin cells and slices of adrenal glands
• All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters
• Effects of high-power laser irradiation on sub-superficial graphitic layers in single crystal diamond