Dual-Band Reflective Optical Sensor Based on GMR-TPS Structure to Detect the Hemoglobin

A novel dual-band reflective optical sensing method for simultaneous measurement of hemoglobin (Hb) concentration and temperature by hybrid guide-mode resonance (GMR)-topological photonic state (TPS) sensor was proposed. The dual-band reflection peaks can be explained by two different mechanisms: one is attributed to the excitation of GMR, and the other is due to the generation of TPS. The GMR worked as the sensing channel of Hb concentration because it is in direct contact with the Hb. Moreover, the TPS worked as the sensing channel of temperature. When the Hb concentration and temperature variation, the two reflection peaks would all shift, but with different sensitivities. Excellent biosensor performance can be obtained by systematically adjusting structural parameters such as grating period (P), grating width (W), grating height (h), and spacer layer thickness (d). Notably, by using the dual-wavelength matrix method, the cross-interference caused by temperature variation is eliminated. The results concluded that the Hb concentration sensitivity and the temperature sensitivity of the proposed sensor could reach 264.44 nm/RIU and 0.061 nm/°C, respectively. The proposed sensor provides a promising sensing strategy for multi-parameter sensing.