Fiber optic dimethyl methyl phosphate fiber optic sensor based on ZIF-8@Ag/PDDA composite film.

• A fiber-optic Michelson interferometric trace DMMP sensor was proposed. • The fiber-optic sensor has the structure of a Michelson interferometer. • ZIF-8@Ag/PDDA as sensing materials is used to enhance the sensitivity. • The sensor has a sensitivity of 45.71 dB/ppm for DMMP. • The sensor has good selectivity and stability. A Michelson interference dimethyl methyl phosphate (DMMP) fiber sensor with a single-mode (SMF)-dislocated single-mode (DSMF)-hollow-core fiber (HCF) structure is proposed. To fabricate the Michelson interference structure of SMF-DSMF-HCF, one end of the DSMF was misaligned and fused to the SMF, the other end was fused to the HCF to generate a reflective surface. The structure, elemental composition, and surface morphology of ZIF-8@Ag were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy after the ZIF-8@Ag/PDDA composite was coated on the surface of DSMF. The result shows that the sensitivity and the detection limit of the sensor are 45.71 dB/ppm and 0.1431 ppb, respectively, and the response/recovery time is around 14/12 s. The sensor also has excellent selectivity and stability. [ABSTRACT FROM AUTHOR]