Increasing demand for accurate on-site monitoring and control of toxic heavy metals ubiquitously found in groundwater requires modern approaches using reliable, portable, and sensitive sensing strategies. Most of the traditional laboratory-based techniques fail to meet these requirements, as they need bulky and expensive instrumentation, require multiple intricate processing steps, and thus require highly trained personnel. Alternative methods to develop cost-effective, scalable, and consistent sensors are thus essential. Such a reliable chemical sensor involves the careful choice of a selective chemoreceptor and a suitable sensitive transducer. Metal-organic frameworks are the class of advanced porous materials recently established as an efficient adsorbent for a variety of contaminants including heavy metals, pesticides, food toxins, etc. Given the advantages of these MOFs such as porosity, thermal stability, structural adaptability, etc., translating them as a selective anchoring material in developing a sensor device for heavy metal ion detection is thus a suitable choice. This thesis aims to develop selective and sensitive sensors for three heavy metal ions namely – chromium, copper, and lead, by adopting the benefits of porous MOFs and utilizing the high evanescent wave absorption capability of U-bent FOS probes. Establishing novel and efficient protocols for a stable, reproducible, and facile strategy for depositing MOFs over silica optical fibers, helped in achieving sensors with excellent sensor parameters that are at par with the permissible limits enforced by the organizations such as the WHO, the EPA, and the BIS