In this study, the potential applicability of Ag/PV A nanocomposites as pH sensing material based on shift of LSPR is reported. A pH sensor is fabricated from low cost fiber optic and optoelectronic components including a Diode LASER (LD) source and a photodiode. The fabricated Ag -PV A nanocomposite is coated on U-bent and tapered U -bent fiber having bent radius of 2.5 mm by dip coating method. For comparison of the sensitivity of the nanocomposite with that of the bulk material we have repeated the experiment with the U -bent fiber having coating of bulk Ag/PV A material. The material characterization and sensor performance results reveal the potential applicability of Ag/PV A nanocomposites as pH sensing material.