An electrochemically reduced graphene oxide chemiresistive sensor for sensitive detection of Hg ion in water samples.

Divalent mercuric (Hg) ion is one of the most prevalent forms of mercury species in waters with high toxicity and bioaccumulation in the human body, for which sensitive and selective detection methods are highly necessary to carry out its recognition and quantification. Here an electrochemically reduced graphene oxide (RGO) based chemiresistive sensor was constructed and used for the detection of Hg ion in various water samples. Monolayer GO sheets were assembled onto interdigitated electrodes, followed by reduction through linear sweep voltammetry and then modification with a single-stranded DNA aptamer.

Biotransformation of indole and its derivatives by a newly isolated Enterobacter sp. M9Z.

In this study, a novel bacterial strain M9Z with the ability of producing indigoids from indole and its derivatives was isolated from activated sludge and identified as Enterobacter sp. according to 16S ribosomal RNA (rRNA) sequence analysis. UV-vis spectrometry and high-performance liquid chromatography-mass spectrometry analysis indicated that the products produced from indole, 5-methylindole, 7-methylindole, and 5-methoxyindole were indigo with different substituent groups, and the possible biotransformation pathways of indole derivatives, i.