Enzyme based biosensor for onsite detection of Chromium

Abstract

Environment has own permissible limit of heavy metals (HMs) in its every component (soil, water and air). Excess use of HMs overcomes this limit hence, leading to toxicity affecting the life on Earth. Due to the oxidizing property of the chromium (Cr), one of the HMs, it is widely used for a number of purposes such as manufacturing of stainless steel, in tannery industry, as cleaning agent for glassware, etc. Chromium has two main stable oxidation states; hexavalent (VI) and trivalent (III), out of which earlier is comparatively more toxic than the later form. Solubility of Cr (VI) in ground water had led to the need of designing a sensitive device which can be quite efficient in monitoring of its presence in the environment. In this review, an attempt has been made to collate information, so far available, on the use of microbial system for intake and detoxification of Cr following use of chromate reductase (CR) enzyme.