Extensive industrial activities resulted in an increase in chromium (Cr) contamination in the environment. The toxicity of Cr severely affects plant growth and development. Cr is also recognized as a human carcinogen that enters the human body via inhalation or by consuming Cr-contaminated food products. Taking consideration of Cr enrichment in the environment and its toxic effects, US Environmental Protection Agency and Agency for Toxic Substances and Disease Registry listed Cr as a priority pollutant. In nature, Cr exists in various valence states, including Cr(III) and Cr(VI). Cr(VI) is the most toxic and persistent form in soil. Plants uptake Cr through various transporters such as phosphate and sulfate transporters. Cr exerts its effect by generating reactive oxygen species (ROS) and hampering various metabolic and physiological pathways. Studies on genetic and transcriptional regulation of plants have shown the various detoxification genes get up-regulated and confer tolerance in plants under Cr stress. In recent years, the ability of the plant to withstand Cr toxicity by accumulating Cr inside the plant has been recognized as one of the promising bioremediation methods for the Cr contaminated region. This review summarized the Cr occurrence and toxicity in plants, role of detoxification genes in Cr stress response, and various plants utilized for phytoremediation in Cr-contaminated regions.

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A facile and rapid enhanced microwave-assisted route for one-pot synthesis has been developed to polymerize indole moiety using two different oxidizing agents for 60 s exposure at 30 6 1 C. As-synthesized conducting polyindoles, obtained by varying the synthesis process and oxidant, have been well characterized by various techniques. UV-vis, FT-IR, and NMR have been used for their structural analysis while gel permeation chromatography, thermogravimetric analysis, and conductivity measurement to evaluate their enhanced properties and to perform a comparative study. Morphological texture of polyindole synthesized via different techniques has studied by scanning electron microscopy analysis. PIn synthesized by KIO 3 (microwave synthesis) exhibit interconnecting texture which may be due to high level of supersaturation of solution under the influence of microwave irradiation. Thereafter, electrical property of spin-coated thin film of polyindole is examined using four probe method and Al metal/semiconducting material Schottky junction. Microwave-assisted polymer shows better performance for Schottky devices due to difference in charge transport, morphological texture, and distribution of M n . The PIn synthesized via microwave irradiation with better charge transport across the metal/polymer interfaces shows the potential of this technique for synthesis of such polymers with enhanced electronic properties.

The synthesized coordination polymer DMTD–Au has a layered structure, in which the layers are stacked via π–π stacking and hydrophobic interaction. It facilitates electron transfer kinetics, which has been utilized in the ultra trace sensing of resorcinol.