By Josh Perry, Editor
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Researchers at the New York University (NYU) Tandon School of Engineering and the Center for Neural Science discovered how to engineer structural defects in graphene to enhance the sensitivity of electrodes composed of the material, which demonstrates potential of engineering graphene properties at the atomic level.

Engineering defects in graphene allows scientists to tune its properties.
(Wikimedia Commons)

“In a surprise finding, the researchers discovered that only one group of defects in graphene’s structure — point defects — significantly impacts electrode sensitivity, which increases linearly with the average density of these defects, within a certain range,” a report from NYU explained.

This breakthrough enables the precise engineering of electrode sensitivity during material production, which opens the door to industrial-scale production of electrodes and to arrays of high-sensitivity electrodes for medical diagnostics and other applications.

The research was recently published in Advanced Materials. The abstract read:

“A major difficulty in implementing carbon?based electrode arrays with high device?packing density is to ensure homogeneous and high sensitivities across the array. Overcoming this obstacle requires quantitative microscopic models that can accurately predict electrode sensitivity from its material structure. Such models are currently lacking.

“Here, it is shown that the sensitivity of graphene electrodes to dopamine and serotonin neurochemicals in fast?scan cyclic voltammetry measurements is strongly linked to point defects, whereas it is unaffected by line defects. Using the physics of point defects in graphene, a microscopic model is introduced that explains how point defects determine sensitivity.

“The predictions of this model match the empirical observation that sensitivity linearly increases with the density of point defects. This model is used to guide the nanoengineering of graphene structures for optimum sensitivity.

“This approach achieves reproducible fabrication of miniaturized sensors with extraordinarily higher sensitivity than conventional materials. These results lay the foundation for new integrated electrochemical sensor arrays based on nanoengineered graphene.”