The development of efficient and high yield techniques and tools are necessary in the current scenario where clean and pollution free water resource are diminishing. In this work, a self-powered and reusable single chambered cylindrical microbial fuel cell (MFC) was developed for toxicity detection in water containing heavy metal ions. The bio-sensing ability of electroactive microbial consortia isolated from industrial wastewater was investigated towards four model heavy metal contaminants (Copper (Cu²⁺), Chromium (Cr⁶⁺), Zinc (Zn²⁺) and Nickel (Ni²⁺)). Their inhibition ratio of 5 mg Cu²⁺, 10 mg Cu²⁺, 20 mg Cu²⁺ was found 5.06%, 31.25%, 78.57%, for 5 mg Cr⁶⁺, 10 mg Cr⁶⁺, 20 mg Cr⁶⁺ was found 6.66%, 80.00%, 93.67% for 5 mg Zn²⁺, 10 mg Zn²⁺, 20 mg Zn²⁺ was found 13.33%, 28.57%, 33.07%, and for 5 mg Ni²⁺, 10 mg Ni²⁺, 20 mg Ni²⁺ was found 6.66%, 18.75%, 23.33% respectively. To examine the reusability of biosensor, Sodium acetate (NaAc) was used as key organic substance. After toxic heavy metals shock the fuel cells are fed with Sodium acetate (NaAc) to investigate their recovery cycle time. After recovery of electroactive microbial consortia, the MFC based biosensor shown sensitive towards the Cu²⁺, Cr⁶⁺, Zn²⁺, and Ni²⁺ at concentrations above 10 mgL⁻¹. Our experimental result showing that, this type of biosensor is very feasible and potential application in toxicity detection of heavy metals polluted water. This type biosensor device is very cost effective in situ system for water contaminants detection.