SPR and Molecular Imprinting-Based Fiber-Optic Melamine Sensor With High Sensitivity and Low Limit of Detection

We report a fiber-optic surface plasmon resonance (SPR) sensor for the detection of melamine using molecular imprinting and an additional layer of silicon in the probe. To achieve the maximum sensitivity and minimum detection limit of the sensor, the thickness of the silicon layer has been optimized. The proposed sensor has a high sensitivity of 76.0 nm/log M. The limit of detection of the sensor has been found to be 4.3 × 10
^-11
M, which when compared with the previously reported values for melamine detection has been found to be the least to the best of our knowledge. Selectivity experiments with dissimilar analytes have also been performed and it has been found that the sensor is highly selective. High sensitivity, low limit of detection, and high selectivity are due to a combined approach of SPR, molecular imprinting, and additional layer of silicon used in the probe. The sensor has numerous other advantages like low cost, ease of handling, capability of online monitoring, and remote sensing.