Ammonia sensing properties of tapered plastic optical fiber coated with silver nanoparticles/PVP/PVA hybrid

•Silver nanoparticles/PVP/PVA hybrids were synthesized at different silver concentrations.•Ammonia sensing properties of silver nanoparticles/PVP/PVA hybrids were investigated.•Proposed sensor showed good sensitivity and selectivity towards ammonia.•Ammonia sensitivity increases with increase in silver nanoparticles concentration.

A tapered plastic optical fiber gas sensor coated with silver nanoparticles/PVP/PVA hybrid is proposed for ammonia gas sensing application. The spectral characteristics of the gas sensor for different silver concentrations were studied at room temperature against various concentrations (0–500 ppm) of ammonia, methanol and ethanol. All the samples exhibited a linear decrease in spectral intensity with the increase in concentration of ammonia whereas it showed little effect for methanol and ethanol. Gas sensitivity studies revealed that the sensors exhibit higher sensitivity at higher concentrations of silver nanoparticles than at lower concentrations. The spectral characteristics of the sensor selectively represented its ammonia sensitivity.