A green method was applied for synthesis of high quality graphene nano-sheets (GR) by simultaneous reduction and exfoliation of as-prepared graphite oxide via microwave irradiation for only 30 s. The highlighted superiority of this developed method over those depicted in the literature is the absence of any hazard reducing, intercalation or chemical activating agents. TEM, FTIR, TGA and XRD analysis confirmed the formation of graphene nanosheets. TEM image reveals a typical wrinkled and crumpled GR structure. A number of graphene layers of 3.0 and interlayer spacing of 0.38 nm were calculated from XRD pattern. Graphene carbon paste modified electrode (GR/CPE) was then fabricated, characterized using SEM, EIS and CV techniques and applied for detection of a potent antimicrobial agent "Chloroxylenol". This developed sensor exhibited excellent performance for detecting bulk Chloroxylenol (LOD of 1.37 x 10(-9) M). Due to the high toxicity of such chlorinated phenolic compound as it can release to the environment through various waste streams and persistent in nature, GR/CPE was also employed for detecting Chloroxylenol in real samples such as its formulation products and water samples. This promising sensor based on ultrafast and cost-effective production of graphene can be employed for quality control analysis of pharmaceutical and environmental samples. (C) 2018 The Electrochemical Society.