Developing smaller, versatile bioelectronics for cell sensing and stimulation

Input-output (I/O) bioelectronics explore electrophysiology-based signals, characterizing the ionic currents that cells use to communicate in organs like the heart or brain.

Output bioelectronics allow sensing of such activity, enabling a deeper understanding of healthy and diseased tissues. Some output bioelectronics are capable of detecting chemical signals and functionality. Input bioelectronics modulate cellular activities by sending electrical or optical signals into the tissue and eliciting a biological response.

Garg et al. reviewed the properties and uses of graphene nanostructures in I/O bioelectronics. This atomically thin 2D material has a large surface area per mass, high conductivity, and transparent optical properties. These characteristics make it an effective platform for detecting and modulating cellular activity through both electrical and optical means.

While many platforms lose functionality at small sizes, 3D graphene nanostructures facilitate bioelectronics of just a few microns in size. They may be used to develop stealthy probes, which avoid recognition as a threat by the body.

Alternatively, remote I/O bioelectronics minimize invasiveness to body. By using graphene nanostructures as photoabsorbers, they can be rapidly heated and wirelessly stimulate cell membranes with optical, rather than electrical, pulses.

“The next step will be multimodality systems,” said author Tzahi Cohen-Karni. “In many published works, you’ll see either the bioelectronics have been used for sensing or actuation, mostly for electrophysiological investigations. Multi-modality should be including chemical sensing, and that’s where we are heading.”

The team emphasized the need for multidisciplinary work in this field, which will lead to improvements in the technology and further our understanding of human electrophysiology.

Source: “Graphene nanostructures for input-output bioelectronics,” by Raghav Garg, Daniel San Roman, Yingqiao Wang, Devora Cohen-Karni, and Tzahi Cohen-Karni, Biophysics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0073870 .