Flexible and Stretchable Gold Three-Dimensional Electrode: Neural Network Induction and Mechanotransduction Observation

Neural cells reside in a three-dimensional (3D) microenvironment where the structure of the nerve circuitry is shaped by the morphology and stiffness of the surrounding extracellular matrix. In this environment, regular exposure to varying mechanical forces triggers biochemical signals during cell mechanotransduction, which plays a crucial role in physiological processes and disease progression. This highlights the need for a flexible 3D platform that integrates cell culture with real-time observation of mechanotransduction. Herein, a 3D flexible and stretchable gold electrode was developed by using a 3D polydopamine-coated polydimethylsiloxane (PDMS)/Ni foam (PDA/PDMS/Ni foam) scaffold as the template. The 3D porous network, combined with the biocompatibility and electrochemical properties of gold nanostructures, enables the electrode to serve as a scaffold for culturing PC12 cells, promoting dopaminergic neural networks with high cell viability. Moreover, the flexible and stretchable 3D Au electrode functioned as a highly sensitive electrochemical sensor for monitoring dopamine (DA) released from the PC12 cell neural networks under mechanical stimuli, which represents the first exploration of continuous DA stimulation at the cellular level in Parkinson's disease. This study presents a promising approach for designing multifunctional 3D stretchable electrochemical sensing platforms, offering insights into mechanotransduction-related neuronal signaling and advancing our understanding of neural function within 3D cellular systems.