Dopamine-integrated all-hydrogel multi-electrode arrays for neural activity recording

Area of Science:

• Neuroscience
• Biomaterials Science
• Electrophysiology

Background:

• Investigating neural circuits is crucial for diagnosing and treating neurodegenerative diseases.
• Traditional rigid electrodes face challenges like mechanical mismatch, foreign body responses, and poor resolution.
• All-hydrogel electrodes offer potential but struggle with conductivity and interlayer adhesion.

Purpose of the Study:

• To develop an all-hydrogel neural electrode with enhanced conductivity and stable adhesion for precise neural recording.
• To overcome limitations of existing neural sensing technologies for neurodegenerative disease research.

Main Methods:

• Constructed a four-layer all-hydrogel neural electrode with conductive, encapsulation, and shielding layers.
• Applied a dual-strategy treatment to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hydrogel for ultra-high conductivity.
• Utilized polyphenol chemistry for adaptive adhesion to ensure stable interlayer bonding.

Main Results:

• Achieved ultra-high conductivity (4176 S cm⁻¹) and precise spatial resolution (∼15 μm) suitable for single neuron recording.
• Demonstrated a tenfold higher signal-to-noise ratio compared to commercial silver electrodes.
• Successfully recorded weak neural activity in epileptic rats and applied cortical stimulation.

Conclusions:

• The developed all-hydrogel neural electrode provides a superior tool for investigating neural circuits in neurodegenerative diseases.
• This technology offers improved performance for both recording neural signals and therapeutic stimulation.
• Enables better understanding of neurodegenerative disease development, function, and treatment strategies.