Graphene coated optical microfiber for aflatoxin B1 detection

We proposed a graphene coated microfiber-based sensor for enhancing Aflatoxin B1 detection at room temperature. The heat-and-pull technique was used to fabricate the microfiber while the graphene layer was coated using a drop-casting technique. Aflatoxin samples are used as a sensor sensing area soaking solution, whereby the prepared graphene-coated microfiber was used as a sensor probe. The sensing is based on the modulation of transmission intensity and wavelength shift induced by the alteration of concentration of aflatoxin B1 from 0 ppm to 10 ppm. There is an increase in sensitivity from 0.129 dBm/ppm to 0.187 dBm/ppm and an increase in resolution from 0.17 ppm to 0.037 ppm by coating graphene on the microfiber sensor. For the graphene coated microfiber-based sensor, the wavelength shift from 1525.37 nm to 1525.19 nm was obtained when the aflatoxin B1 concentration was increased from 0 to 10 ppm. It reveals a sensitivity of 0.018 nm/ppm with a linearity of more than 90 %. This finding shows that the proposed sensor can be used to detect various concentration of Aflatoxin sample with the ability to offer real time measurement.