Surface plasmon resonance based optical fiber sensor for atrazine detection using molecular imprinting technique

We reported a successful effort for fabrication and characterization of surface plasmon resonance based fiber optic sensor to detect atrazine by molecular imprinted technique. The fabrication of sensing probe is done by coating a 40 nm thick silver film over the unclad core of an optical fiber. Further, an over layer of molecular imprinted (MIP) polymer having atrazine as template molecule has been coated over Ag coated region. Spectral interrogation method has been used for characterization of the probe. A red shift of 38 nm in resonance wavelength has been observed for atrazine concentration range of 0 M-10−7 M. Sensitivity of the sensor has been found to be 17.34 nm/log M for atrazine concentration of 10−12 M. The sensor has lowest detection limit of 1.92 × 10−14 M and quantification limit of 7.61 × 10−14 M. Sensor has been found to be highly selective as well as highly sensitive due to a combined approach of molecular imprinting and surface plasmon resonance. Besides them, sensor has numerous advantages such as low cost, fast response, immune to electromagnetic interface and capability of online monitoring and remote sensing.