Plasmonic fiber-optic aptasensor for the detection of bisphenol A

A plasmonic fiber-optic aptamer sensor based on a gold-coated tilted fiber Bragg grating (TFBG) was constructed for bisphenol A (BPA) detection with an ultralow detection limit (LOD). A thiol-functionalized BPA-specific DNA aptamer is covalently immobilized on the surface of the gold-coated TFBG to achieve highly selective molecular recognition. The proposed sensor exhibits a linear response to BPA in the concentration range of 1.0×10−16 to 1.0×10−6 M, with a detection limit of 1.14×10−17 M. In addition, the proposed sensor exhibits excellent specificity for BPA, and the consistent results were obtained in tap water samples. These findings confirm that the proposed TFBG-SPR aptamer sensor provides a robust, label-free, and real-time detection platform with a detection limit several orders of magnitude lower than previously reported optical biosensors, which demonstrates its great potential for applications in environmental and food safety monitoring.