Biomimetic Gradient Porous Core–Shell Fibers with Enhanced Gas Sensing for CO-Temperature Dual-Mode Early Fire Warning

Highlights A biomimetic gradient porous core–shell fiber with enhanced gas-sensing capabilities for CO-temperature early fire warning is fabricated via a coaxial wet-spinning technology. The gradient porous sheath with SnO 2 /In 2 O 3 heterojunction endows enhanced CO gas-sensing performance with high sensitivity, low detection limit and improves the CO respond of by 15%. The CO-temperature dual-mode sensing fiber integrated with a wireless early fire-warning system achieves a rapid respond to fire in ~3 s and detects 10 ppm CO gas within 19 s.