A 1μm diameter tip fiber-based surface plasmon resonance system for single unit optical neural recording

Area of Science:

• Biomedical Engineering
• Neuroscience
• Optical Sensing

Background:

• Accurate measurement of neuronal activity is crucial for understanding brain function.
• Existing methods for neuronal recording have limitations in sensitivity and specificity.
• Optical techniques offer potential for non-invasive and high-resolution monitoring.

Purpose of the Study:

• To develop a gold-deposited optical fiber sensor system for surface plasmon resonance (SPR) based optical measurement of neuronal activity.
• To enhance the sensitivity of localized SPR and enable precise, safe contact with cellular membranes.
• To integrate the SPR system with a patch-clamp setup for simultaneous optical and electrical recordings.

Main Methods:

• Fabrication of pencil-shaped optical probes with a 1 μm tip diameter using wet etching and gold evaporation.
• Integration of the SPR system with a conventional patch-clamp system.
• Simultaneous optical and electrical recording on a single neuron.

Main Results:

• Successful fabrication of tapered optical probes.
• Simultaneous optical and electrical signals were recorded from a single neuron.
• Observed changes in optical and electrical signals upon capsaicin stimulation, despite minor optical signal clarity.

Conclusions:

• The developed SPR optical fiber sensor system enables simultaneous optical and electrical recordings of neuronal activity.
• The sharp optical probe design enhances localized SPR sensitivity and ensures safe cellular contact.
• The system holds promise for applications in localized optical stimulation and in vivo optical neuroprosthetic devices.