Fig. 1. Polarization correlation spectrum of the TFG. (a) Optical path coupling principle of probe type 81°TFG; (b) transmission type 81°TFG; (c) probe type 81°TFG

Fig. 2. Schematic diagram of the experimental system

Fig. 3. RI sensitivity calibration of the dual-channel probe type 81°TFG sensor. (a) Probe type 81°TFG1; (b) probe type 81°TFG2

Fig. 4. Surface modification and biofunctionalization process of the probe type 81°TFG-LSPR

Fig. 5. RI sensitivity of probe type 81°TFG before and after modification

Fig. 6. FESEM images of the probe type 81°TFG. (a) Modified with AuNs; (b) modified with AuNs and GO

Fig. 7. Energy spectrum of the probe type 81°TFG surface modified with AuNs and GO

Fig. 8. AFP antigen detection control experiment of dual-channel sensor. (a) Change curve of the spectrum with mass concentration; (b) change curve of the resonance wavelength shift with time

Fig. 9. Change curve of resonant wave long red shift with anti-primary solution quality concentration

Fig. 10. Clinical experiment spectrum and resonance wavelength changes of dual-channel biosensor. (a) Change curve of the spectrum; (b) change curve of the wavelength