Two highly sensitive concentration sensors have been developed using FBG and LPG. Designed sensors are used to measure Zn(ppm) in drinking water from different areas. Results obtained by the two sensors are comparably equal. Sensitivities of FBG & LPG sensors are found to be 3.47 & 712 pm/ppm respectively. Results of our sensors are in agreement with that of AAS on samples, hence reliable.