Graphene, a new member of the carbon family, has attracted enormous attention due to its very peculiar properties like high surface area, mechanical strength, and conductivity. Moreover, graphene is exceptionally biocompatible if used as a substrate for immobilization of enzymes, bioreceptor molecules, or whole cells. Although it was isolated on a mass scale quite recently (in 2004), its use as a signal enhancing material in chemo- and biosensors has already seen a rapid growth. The aim of the present review is to bring out important advances of graphene-based sensing and, particularly, those related to rapid detection and quantization of the toxin, explosive, pesticide, pathogen, and microbe analytes. These analytes are important hazardous determinants of a safe living environment. This chapter therefore summarizes selected key strategies developed toward devising sensing systems with graphene and derivatives of graphene to detect and determine these hazards to safe living.