<p>In order to cope with the difficult problem of low sensitivity detection of low concentration samples and realize the high sensitivity detection of target analytes, a bifunctional sensor was designed in this study by combining the high quality factor (Q-factor) characteristic of Fano resonance with the advantage of the wide dynamic range of plasmon-induced transparency (PIT) effect. By introducing an asymmetric structure to break symmetry, the sensor is able to induce the generation of both PIT effect and Fano resonance effect in a single device, which further enhances the comprehensive detection performance of the sensor. Finite-element simulations reveal that the PIT window achieves a maximum sensitivity of 2.84 THz/RIU, while the transmission peak influenced by Fano resonance exhibits a Q-factor of 18.06 and a figure of merit (FOM) of 10.44 RIU⁻¹. Furthermore, by adjusting the structural parameters, the flexible switching of bifunctionality can be realized, which significantly enhances the accuracy of the substance detection and the range of sensing applications. The results show that the design incorporates the excellent characteristics of Fano resonance and PIT effect to achieve the high sensitivity requirement of the sensor and successfully overcomes the performance limitation of the single function of the traditional sensor.</p>