Fig. 1. Equation of H₂O₂ reaction catalyzed by HRP

Fig. 2. Preparation principle and flowchart of sensor

Fig. 3. Schematic of sensor measurement system

Fig. 4. Surface topography of fiber and its enlarged view. (a)(e) Bare fiber; (b)(f) silanized fiber; (c)(g) aldehyde cross-linked fiber; (d)(h) HRP immobilized fiber

Fig. 5. EDS diagrams of different fibers. (a) Bare fiber; (b) HRP immobilized fiber

Fig. 6. Performance curves of sensors with different volume fractions of glutaraldehyde. (a) Sensitivity; (b) transmission spectra

Fig. 7. Performance curves of sensor at different aldehyde cross-linked times. (a) Sensitivity; (b) transmission spectra

Fig. 8. Performance curves of sensors at different mass concentrations. (a) Sensitivity; (b) transmission spectra

Fig. 9. Performance curves of sensors at different fixed times. (a) Sensitivity; (b) transmission spectra

Fig. 10. Influence of temperature of H₂O₂ solution on sensor sensitivity

Fig. 11. Results of different indicators of sensors. (a) Time response; (b) repeatability; (c) selectivity; (d) lower limit of detection