Recent trends in surface plasmon resonance based fiber–optic gas sensors utilizing metal oxides and carbon nanomaterials as functional entities

Rapid industrialization and urbanization have unequivocally eased the lives of people to an appreciable extent, which however, has been achieved at the cost of an unprecedented degradation and pollution of natural environment. The continual high–concentration subjection of various gases and organic vapours instigated by their large–scale production plus consumption as raw materials in myriad industrial processes intensely jeopardizes living beings, aquatic life, food and water resources, and ultimately, planet ecosystem. This makes swift, specific and unambiguous detection of such gases pre–eminent for industrial safety as well as environment monitoring. This review paper focuses on the recent advancements on fiber–optic gas sensors utilizing surface plasmon resonance (SPR) sensing technology. Initiating with an overview of the design and implementation of fiber–optic SPR gas sensors, the paper summarizes the algorithms and instrumentation indispensable for fabricating and analysing the performance of these sensors. Citing exemplary instances from literature, the paper comprehensively discusses various contemporary sensing structures used for fabricating fiber–optic gas sensors exploiting the advantages furnished by metal/semiconductor oxides as well as carbon nanomaterials including carbon nanotubes and graphene. Lastly, the paper outlines the challenges and available opportunities in this avenue.