biosensor based on the plasmonic effect for glucose detection

Aim and background: the high accuracy of optical sensors that work based on the phenomenon of surface plasmon resonance (spr) has made them suitable for biological detection. these sensors are capable of detecting small changes in the refractive index (ri) of the medium surrounding the sensor’s surface. the spr sensor with au thin film has been fabricated and experimentally demonstrated for glucose detection. the proposed sensor has several advantages including simplicity in design, low manufacturing cost, and label-free detection.methods: the technique used for glucose sensing is the angular survey method based on the kretschmann arrangement to envisage sharp spr reflectance curves. the au thin film was deposited on a glass slide by the thermal evaporation method. to investigate spr for sensing applications, the kretschmann configuration was designed. in this setup, the laser light passes through the prism at different angles and reaches the matched oil layer, the glass slide, the au thin layer, and then the glucose layer, respectively. then, the reflected light was measured from the interface of gold and glucose thin films.results and discussion: the spr reflectance curves for the kretschmann structure of the au/air and au/glucose thin films were drawn and the minimum reflectance was measured at an angle of 51 and 53 degrees, respectively. the increase in minimum reflection was due to the absorption of glucose on the gold surface and the change in refractive index.conclusion: the present study exhibits a gold-based prism-coupled spr biosensor for effectual sensing of the 200 mg/dl glucose concentration at a wavelength of 632.8 nm.