Plasmonic sensor for hydrogen sulphide in saliva: Multisensor platform and bag format

In recent years, there is a growing demand for optical sensors given their analytical properties, and the possibility of in situ implementation. Among all the types of optical sensors, plasmonic sensors have aroused great interest in the scientific community. In this work, the ability of a plasmonic sensor based on AgNPs retained on a Nylon surface is studied to determine hydrogen sulfide, which can be an indicator of oral diseases. This compound produces a color change of the sensor from yellow to brown directly related to its concentration. The sensor response is evaluated in two different assay formats such as bag and well microplates. The figures of merits of both methodologies have been obtained and compared. The advantages and disadvantages of the different formats have been shown. Finally, the sensor is applied to quantify sulfides in real saliva. Concentrations ranged from 30 μ L−1 to 600 μ L−1 have been obtained for the voluntaries. Besides that, in this approach the RGB coordinates from images have been used as analytical signal too. The results achieved have demonstrated that the sensor and the methodology applied provide good selectivity, sensibility, rapidity, it is non-invasive and it can be used as indirect method to measure problems in the oral cavity. [Display omitted] •A novel in situ plasmonic sensor for H2S in saliva samples has been developed.•Two different formats have been assayed, bag samplers and multisensor platforms.•Saliva from different persons has been analyzed by using both formats.•The RGB coordinate from sensor imagens have been correlated with reflectance diffuse signals.•Good LODs and LOQs have been achieved to determine halitosis problem.