Flexible Nanoarchitectonics for Biosensing and Physiological Monitoring Applications

Flexible and implantable electronics hold tremendous promises for advanced healthcare applications, especially for physiological neural recording and modulations. Key requirements in neural interfaces include miniature dimensions for spatial physiological mapping and low impedance for recognizing small biopotential signals. Herein, a bottom-up mesoporous formation technique and a top-down microlithography process are integrated to create flexible and low-impedance mesoporous gold (Au) electrodes for biosensing and bioimplant applications. The mesoporous architectures developed on a thin and soft polymeric substrate provide excellent mechanical flexibility and stable electrical characteristics capable of sustaining multiple bending cycles. The large surface areas formed within the mesoporous network allow for high current density transfer in standard electrolytes, highly suitable for biological sensing applications as demonstrated in glucose sensors with an excellent detection limit of 1.95 mu m and high sensitivity of 6.1 mA cm(-2) mu M-1, which is approximately six times higher than that of benchmarking flat/non-porous films. The low impedance of less than 1 k ohm at 1 kHz in the as-synthesized mesoporous electrodes, along with their mechanical flexibility and durability, offer peripheral nerve recording functionalities that are successfully demonstrated in vivo. These features highlight the new possibilities of our novel flexible nanoarchitectonics for neuronal recording and modulation applications.

Automated summary

Flexible and low-impedance mesoporous gold electrodes were developed through a combination of bottom-up mesoporous formation technique and top-down microlithography process. These electrodes exhibited excellent mechanical flexibility, stable electrical characteristics, and high surface area, making them suitable for high current density transfer and biological sensing. In vivo experiments demonstrated successful peripheral nerve recording functionalities, highlighting the potential of these electrodes for neuronal recording and modulation applications.