There is fast growing research on designing and improving the metal recognition methodologies in the ecosystems and biological media. The fluorescent based techniques proved a mile stones for non-invasive metal sensation and quantification in the multichannel environment. Metals as the natural components of Earth's crust are generally present in trace concentrations in the environmental samples where the humic substances have complexation affinity toward them. Iron, zinc and copper are the 1 st , 2 nd and 3 rd adequate elements indispensable to the body in trace playing the crucial roles in many biological processes. However, the unregulated amounts either as excess or deficient may exacerbate deterioration to the vital organs and triggered the progression of complications. Beside these three essential elements, mercury is widely considered to be one of the most hazardous pollutants and highly dangerous elements due to its recognized accumulative and toxic characters in the environment and the ecosystem. In the current scenario, we have tried to summarize the maximum amount of recently developed fluorescent signaling materials for the Cu 2+ , Fe 2+ / Fe 3+ , Zn 2+ and Hg 2+ . The spectral shifting in the molecules on metal chelation, mode of complexation and stoichiometries of resulting adducts have been discussed in detail. Furthermore, the molecules which have been reported as intracellular metal detector via bioimaging are specifically highlighted that might be useful for the design and development of cell viable and membrane permeable molecular probes in the future perspective.