Temperature self-compensated double-hole optical fiber surface plasmon resonance sensor for detection of chiral (R,S)-anatabine

• Dual-channel SPR-MZI optical fiber sensor for chiral drug enantiomer detection. • Au/R/Tar@UiO-66-NH 2 and Au/TiO 2 /S/Tar@UiO-66-NH 2 have high selectivity. • The sensitivities are 51.743 pm/nM (R) and 49.512 pm/nM (S) respectively. • The sensor can perform self-compensation for temperature. Anatabine, as an important alkaloid component in tobacco, has potential application value in flavor regulation and the development of characteristic tobacco products. However, traditional detection methods have limitations such as complex sample processing and weak anti-interference ability. In this regard, this study proposes a chiral molecular enantiomeric selectivity sensor based on double-hole optical fiber (DOF). Multi-parameter detection is achieved by integrating surface plasmon resonance (SPR) and Mach-Zehnder interferometer (MZI) technologies. It innovatively adopts a cascade structure of single-mode fiber (SMF)- multimode fiber (MMF)-DOF. Nano-metal films are deposited in the dual-hole fiber region to excite the SPR effect, and the UiO-66-NH 2 metal–organic framework (MOF) is coated as the chiral recognition carrier. Au/R-Tar@UiO-66-NH 2 and Au/TiO 2 /S-Tar@UiO-66-NH 2 composite films were respectively modified on both sides of the sensor to stimulate surface plasmon resonance 1 (SPR-1) and 2 (SPR-2) as sensing channels 1 and 2. This design can achieve specific recognition of liquid (R)-(+)-anatabine and (S)-(−)-anatabine. Moreover, single-mode optical fibers and dual-hole optical fibers can be combined to form MZI, which serves as the sensing channel 3 to eliminate temperature interference. The detection sensitivities of (R)-(+)-anatabine and (S)-(−)-anatabine are 51.743 pm/nM and 49.512 pm/nM respectively, and the minimum detection limit is 0.386 nM. This design provides an innovative detection solution for chiral drug enantiomer analysis in complex environments.