<p>Reliable gas sensing in integrated photonic platforms remains challenging due to inherently weak light–matter interactions in compact dielectric devices and the sensitivity of conventional resonators to fabrication-induced scattering losses. In this work, we numerically investigate a dual topological micro-ring resonator designed for robust gas and temperature sensing in the mid-infrared regime. The proposed sensor employs valley photonic crystal waveguides with inversion-asymmetric hexagonal lattices, supporting topologically protected edge states within a complete transverse-electric bandgap. Two coupled micro-ring resonators integrated into a Z-shaped waveguide induce strong near-field localization and enhanced evanescent-field interaction with the surrounding gas, achieving a high optical confinement factor (Γ ≈ 36.8%) in the low-index (air) region while maintaining low-loss propagation. The transmission response exhibits sharp resonance dips with a free spectral range of ~ 40&#xa0;nm, a linewidth of 0.25&#xa0;nm, and a quality factor on the order of 10⁴. Temperature sensing is realized via the thermo-optic effect of silicon, yielding a linear resonance shift with a sensitivity of 0.13&#xa0;nm °C^-1. Gas sensing performance is evaluated for a refractive index change of Δn = 4.6 × 10^− 4, achieving a high sensitivity of 820&#xa0;nm RIU^-1, enabled by strong optical energy confinement in the air regions. The results demonstrate a compact, low-loss, and multifunctional sensing platform that combines topological photonics with enhanced field confinement, offering a promising route for integrated mid-infrared sensing applications.</p>