Formic acid gas sensor based on coreless optical fiber coated by molybdenum disulfide nanosheet

Molybdenum disulfide (MoS2) nanosheets were prepared by the method of liquid phase ultrasonic separation. It is coated on the surface of single mode-no-core-single mode (SNS) fiber structure by drip coating method, which realizes the detection of formic acid gas under room temperature. The corresponding sensing performance has been discussed in the concentration range of 0–250 ppm and 0–1100 ppm, respectively. The good selectivity, repeatability and response/recovery characteristics have been experimentally demonstrated and used for exploring an effect method to greatly improve the sensitivity of the formic acid gas sensor. This passive optical fiber probe has the promising potential application in medical and industrial production process for determining the formic acid concentration at room temperature.