Temperature-compensated multiparameter SPR fiber-optic sensor for EGFR biomarker detection based on multi-mechanism signal amplification.

Traditional surface plasmon resonance (SPR) sensors generally rely on a single sensing interface, making it difficult to achieve selective enhancement of different response mechanisms, thereby limiting their multiparameter detection capability and sensing performance. In this work, a multi-mechanism signal amplification SPR fiber-optic sensing platform based on interface-cooperative regulation is proposed for the simultaneous detection of epidermal growth factor receptor (EGFR) exon 20, pH, and temperature, while enabling real-time temperature compensation. By constructing functional interfaces with distinct physicochemical characteristics, synergistic signal amplification through multiple sensing mechanisms is achieved. Specifically, the Ag interface utilizes stable Ag-S bonding to enable efficient immobilization of probe DNA for the specific recognition of exon 20; the hydroxyl-rich Ag/TiO2 interface facilitates the stable assembly of the PAA/CS functional layer to form a pH-responsive channel; and the Ag/MoS2/PDMS composite structure provides temperature monitoring and compensation through its thermosensitive characteristics. Meanwhile, the synergistic optical regulation of the high-refractive-index TiO2 layer and the two-dimensional MoS2 material enhances the local electromagnetic field and enables effective spectral separation among multiple sensing channels, resulting in improved sensing performance. Experimental results demonstrate average sensitivities of 0.178 nm/nM, -22.59 nm/pH, and -4.439 nm/°C for exon 20, pH, and temperature detection, respectively. By introducing a real-time temperature compensation strategy, the accuracy and reliability of EGFR exon 20 detection are further improved. The proposed sensing platform provides a promising approach for lung cancer biomarker analysis and multimodal physiological monitoring in complex biological environments.