Gold Nanoparticle/Carbon Fiber Hybrid Structure from the EcoFriendly and Energy-Efficient Process for Electrochemical Biosensing

The carbon fiber/metal nanoparticle hybrid structure is a widely studied material combination for various fields such as energy storage, highperformance composites, and biomedical tools. The versatile carbon fiber/gold nanoparticle structure was prepared using an eco-friendly and energy-efficient fabrication process to address the sustainability issue. First, cellulose fiber was prepared by an eco-friendly lyocell process. The study obtained high mechanical strength of the lyocell fiber through high cellulose contents, strict pulp dissolution conditions, modified spinning, and thermal elongation processes. Then, the lyocell fiber was changed to carbon fiber with stabilization under 5% tension and carbonization, resulting in high mechanical strength and Young's modulus. Finally, gold nanoparticles were electrochemically deposited on the lyocell-based carbon fiber surface. The electrochemical properties of the carbon fiber/gold nanoparticle system were drastically improved due to the high surface area of the nanostructured gold particles. Enhanced electrochemical property and biocompatibility from non-toxic material selection enabled the carbon fiber/gold nanoparticles for dopamine detection, a representative electrochemical biosensor. The detection result demonstrated that the hybrid structure provided high sensitivity and selectivity for dopamine sensing. Overall, this fabrication strategy opens up numerous application opportunities to address eco-friendly and sustainable development requirements.