The surface plasmon resonance (SPR) technique is a remarkable tool, with applications in almost every area of science and technology. Sensing is the foremost and majorly explored application of SPR technique. The last few decades have seen a surge in SPR sensor research related to sensitivity enhancement and innovative target materials for specificity. Nanotechnological advances have augmented the SPR sensor research tremendously by employing nanomaterials in the design of SPR-based sensors, owing to their manifold properties. Carbon-based nanomaterials, like graphene and its derivatives (graphene oxide (GO)), (reduced graphene oxide (rGO)), carbon nanotubes (CNTs), and their nanocomposites, have revolutionized the field of sensing due to their extraordinary properties, such as large surface area, easy synthesis, tunable optical properties, and strong compatible adsorption of biomolecules. In SPR based sensors carbon-based nanomaterials have been used to act as a plasmonic layer, as the sensitivity enhancement material, and to provide the large surface area and compatibility for immobilizing various biomolecules, such as enzymes, DNA, antibodies, and antigens, in the design of the sensing layer. In this review, we report the role of carbon-based nanomaterials in SPR-based sensors, their current developments, and challenges.

A fiber optic dopamine sensor is realized utilizing surface imprinted carbon nanotube platform and surface plasmon resonance technique. The sensor possesses dynamic range of 0-150 µM and detection limit of 2.1 µM.

A fiber optic SPR sensor has been reported for Sulfamethoxazole (SMX). Silver film has been utilized as plasmonic material with a selective sensing layer of molecularly imprinted polymer on the surface of carbon nanotubes.

A fiber optic based LSPR sensor has been characterized for the sensing of hydrazine. The probe consists of silver nanostructures for exciting LSPR and palladium nanoparticles for changing response (peak absorbance wavelength) with hydrazine concentration. The hydrothermal diffusion of hydrazine on palladium nanoparticles leads to red shift in peak absorbance wavelength with increasing concentration.

Hydrazine, a well-known reactive base and a critical reducing agent is a colorless liquid used substantially in industrial as well as in military applications [1]. Despite its acknowledged and long established applications, it is considered as a human carcinogen on minute levels of exposure through inhalation, ingestion or eye/skin contact. Hence, trace level detection of hydrazine is necessary for health safety. Various methods like liquid chromatography, spectrometry, electrochemical and optical have been reported for hydrazine sensing. We report a fiber optic SPR probe based on plasmonic property of silver thin film and palladium decorated MWCNTs engraved in polypyrrole matrix as sensing layer. Polypyrrole is a well-known conducting polymer used extensively for detection of hydrazine by charge transfer reactions leading to change in both its electrical and optical properties [2]. It also helps in attachments of Palladium-MWCNTs composite on silver coated probe.