In this work, a realized Fano resonance due to the coupling between two 1DTPC is pro posed for refractive index sensing with an ultra-high-quality factor of 106. The generated Fano can be assigned to the coupling between topological edge states of two 1D TPCs. The resulting Fano peak is characteristic with a high transmission value reach to 99% with high sensing performance parameters making the proposed sensor a novel detector for refractive index. The proposed coupling 1D TPCs show a high sensitivity value of 888.252 nm/RIU, ultra-high-quality factor and figure of merit value reach 106, and perfect detection limit value of 10−7. The proposed coupling 1D TPCs provides a straightforward platform for sensing refractive index applications with high performance.