Semiconducting electrodes for neural interfacing: a review

Abstract

Neural recording, stimulation, and biochemical sensing using semiconducting electrodes in both electrical and optical domains are discussed. Their differences from metallic electrodes from the application and characterization perspective are highlighted.

Control of Neuronal Survival and Development Using Conductive Diamond

“…This capacitive charge transfer involves a redistribution of charged chemical species within the electrolyte without any direct charge exchange across the electrode/electrolyte interface. 44,45 Such a capacitive charge transfer is considered safer than the Faradaic charge transfer for biological applications. 46 In a recent study, we demonstrated oxygen annealing as an effective method to enhance the capacitive photoelectric responses of N-UNCD to NIR illumination.…”

“…For example, in saline solution, hydrogen-terminated N-UNCD shows an illumination induced Faradaic charge transfer mechanism, while oxygen-terminated N-UNCD electrodes predominantly exhibit capacitive photocurrents. This capacitive charge transfer involves a redistribution of charged chemical species within the electrolyte without any direct charge exchange across the electrode/electrolyte interface. , Such a capacitive charge transfer is considered safer than the Faradaic charge transfer for biological applications . In a recent study, we demonstrated oxygen annealing as an effective method to enhance the capacitive photoelectric responses of N-UNCD to NIR illumination .…”

2D Optimized Electrodes for Highly Sensitive and Biocompatible Neural Recording

“…Quantum dots (QDs) of two-dimensional (2D) materials possess high specific surface area and activity, making them promising candidates for enhancing the sensitivity of neural electrodes as surface modification materials. − WSe 2 and WS 2 QDs, as multifunctional semiconductor materials, have high conductivity due to their unique electrode structure, as well as excellent catalytic properties, high stability, low toxicity, and simple preparation methods conducive to mass production. − WS 2 QDs, in particular, demonstrate smaller lattice mismatch and higher electrochemical catalytic activity, rendering them particularly promising across various applications. , In this work, we prepared high-performance neural electrodes based on 2D WSe 2 /WS 2 QDs (2D optimized electrode) with excellent conductivity and high specific surface area, achieving low impedance and high cathode charge-storage capacity (CSCc), which enhanced the sensitivity of neural signal acquisition. Additionally, the 2D optimized electrodes exhibited outstanding antioxidant activity and CAT enzyme-like activity, which can improve biocompatibility by reducing neuroinflammatory responses through the elimination of free radicals generated during electrode implantation into brain tissue.…”

Simultaneous Presentation of Dexamethasone and Nerve Growth Factor via Layered Carbon Nanotubes and Polypyrrole to Interface Neural Cells

“…Approximately 1 billion individuals worldwide suffer from neurological diseases, including but not restricted to Alzheimer’s, Parkinson’s disease, stroke, multiple sclerosis, epilepsy, migraine, brain traumas, and neuroinfections, which cause around 8 million deaths each year . Neural electrodes, a kind of microelectronic device that can be implanted in the target tissue to record neural signals or provide specific stimulation for the functional recovery of nerve pathways, are considered as powerful tools for the diagnosis and treatment of neurological diseases. , In recent years, neural electrodes are widely used in the study of fundamental brain-nervous system interactions and the treatment of common neurophysiological disorders, such as Parkinson’s disease, epilepsy, deafness, blindness, and movement disorders. , However, a growing body of research has found that implantable neural electrodes cause acute insertion trauma, chronic inflammation, and foreign body reactions, resulting in the decrease of recording/stimulating performance and the shortening of the electrode working period . The insertion of neural electrodes into the brain tissue unavoidably disrupts the blood-brain barrier, damages blood vessels, and causes the death of neural cells around the electrodes, leading to acute inflammatory reactions characterized as the release of inflammatory factors and activation of microglia cells and astrocytes .…”

“…2 Neural electrodes, a kind of microelectronic device that can be implanted in the target tissue to record neural signals or provide specific stimulation for the functional recovery of nerve pathways, are considered as powerful tools for the diagnosis and treatment of neurological diseases. 3,4 In recent years, neural electrodes are widely used in the study of fundamental brain-nervous system interactions and the treatment of common neurophysiological disorders, such as Parkinson's disease, epilepsy, deafness, blindness, and movement disorders. 5,6 However, a growing body of research has found that implantable neural electrodes cause acute insertion trauma, chronic inflammation, and foreign body reactions, resulting in the decrease of recording/stimulating performance and the shortening of the electrode working period.…”