Fig. 1. Schematic diagram of DR-LPFG modified with nano-TiO₂ particles

Fig. 2. FESEM images of nano-TiO₂-intergrated DR-LPFG. (a) 300×; (b) 5000×

Fig. 3. Biofunctionalization of the DR-LPFG sensor. (a) nano-TiO₂ immobilization; (b) sensor surface modified with anti-H9N2 MAbs; (c) sealing of redundant binding sites

Fig. 4. Diagram of experimental system. (a) Schematic diagram; (b) experimental setup

Fig. 5. RI response of DR-LPFG sensor modified with nano-TiO₂. (a) Transmission spectra evolution of the sensor versus the RI of NaCl solution; (b) RI sensitivity change of the sensor before and after nano-TiO₂ coating

Fig. 6. Variation of dual-resonance spacing of the biosensor. (a) anti-H9N2 MAbs immobilization; (b) sealing of redundant binding sites with SMPSF

Fig. 7. Transmission spectra evolution of the DR-LPFG against the mass concentration of H9N2 AIV

Fig. 8. Relationship between dual-peak spacing of sensor and different parameters. (a) Different mass concentrations of H9N2 AIV solutions; (b) logarithm of different mass concentrations of H9N2 AIV solutions

Fig. 9. Variation of the dual-resonance spacing of the DR-LPFG based biosensor during the specific test