Optical Fibers Functionalized with Single-Walled Carbon Nanotubes for Flexible Fluorescent Catecholamine Detection

Area of Science:

• Biomedical Engineering
• Neuroscience
• Analytical Chemistry

Background:

• Catecholamine dynamics are crucial for human health and disease, but current detection methods are limited.
• Existing fluorescent sensors are primarily for animal models, hindering clinical diagnostic applications.

Purpose of the Study:

• To develop a novel fiber-optic based sensor for catecholamine detection with potential for clinical translation.
• To demonstrate the feasibility of near-infrared fluorescent catecholamine sensors (nIRCats) for dopamine detection.

Main Methods:

• Functionalization of optical fibers with single-walled carbon nanotube (SWNT)-based near-infrared catecholamine sensors (nIRCats).
• Testing sensor response to dopamine in biologically relevant concentrations (10 nM–1 μM).
• Assessing sensor stability in human blood plasma and long-term utility in biofluids.
• Development of a compact, mobile dual-near-infrared fiber photometry rig.

Main Results:

• nIRF fibers demonstrated sensitive dopamine detection within the 10 nM–1 μM range.
• Sensors maintained minimal responsivity loss after 16 hours in human blood plasma.
• Detection of dopamine was successful in small volumes (10 μL) of biofluids up to 24 weeks post-synthesis.
• The photometry rig successfully detected dopamine in acute brain slices.

Conclusions:

• Fiber-optic based nIRCats offer a promising platform for convenient and less invasive catecholamine detection.
• This technology expands the available tools for studying catecholamine dynamics in clinical settings.
• The developed system holds potential for improved diagnostics and research in neurological disorders.