Electrophysiology is an invaluable technique for studying the electrical activity of neurons in the brain and has important clinical applications. The use of nanowire and nanotube intracellular electrode recording devices has improved the spatial resolution and sensitivity of electrophysiological techniques. However, intracellular recordings within thick tissues is limited by the length of the nanotube/nanowire electrode, which has insufficient stiffness at lengths greater than 10 µm. As a result, existing nanodevices cannot be used to record neuronal electrical activity within thick tissue slices ex vivo or within deep tissue structures in vivo.
To overcome this challenge, researchers at Toyohashi University of Technology in Japan have developed a long nanoscale-tipped microneedle electrode. The 120 µm-long “nanotower” electrode is sufficiently strong to penetrate thicker and deeper tissue structures, overcoming the limitations of conventional nanotube and nanowire electrodes. The development of this device, described in an article published in Small, diversifies the scope of preclinical and clinical applications of nanoelectrodes in electrophysiology.