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Mine wastewater often contains dissolved metals at concentrations too low to be economically extracted by existing technologies, yet too high for environmental discharge. The most common treatment is chemical precipitation of the dissolved metals using limestone and subsequent disposal of the sludge in tailing impoundments. While it is a cost‐effective solution to meet regulatory standards, it represents a lost opportunity. In this study, we engineered Escherichia coli to overexpress its native NikABCDE transporter and a heterologous metallothionein to capture nickel at concentrations in local effluent streams. We found the engineered strain had a 7‐fold improvement in the bioaccumulation performance for nickel compared to controls, but also observed a drastic decrease in cell viability due to metabolic burden or inducer (IPTG) toxicity. Growth kinetic analysis revealed the IPTG concentrations used based on past studies lead to growth inhibition, thus delineating future avenues for optimization of the engineered strain and its growth conditions to perform in more complex environments. [ABSTRACT FROM AUTHOR]

The pencil-drawn sensor is expected to enable a simple, low-cost, and reproducible paper-based sensor platform for widely deployed wireless environmental monitoring of NO2. Herein, we demonstrated a rapid prototyping of chemiresistor-type NO2 sensor by mechanical abrasion of an 8B pencil to form a stripe of uniform graphitic coating on printed silver interdigitated electrodes (IDEs). The Ag IDEs not only offer a low resistance but also provide the assembly of Ag nanoparticles into exfoliated graphene sheets for the paper-based NO2 gas sensors in order to realise much higher sensitivity and better reproducibility comparing with pencil-drawn sensors directly on weighing paper. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate gravure printing of crumpled graphene ink to obtain a highly porous pattern of interdigitated electrodes, leading to an interdigital microsupercapacitor (MSC) on a flexible polyimide substrate. During the process of synthesizing crumpled graphene ink, Mg(OH)2 nanosheets as nanospacers were inserted into graphite oxide layers, resulting in sufficient crumples in graphene nanosheets to prevent the graphene sheets from restacking to enhance the ion transport and expose the electrochemical active area with oxygen-containing groups to provide more pseudo-capacitance. The gravure-printed interdigital MSCs achieved a high energy density (1.41 mW h cm−3 at 25 mW cm−3) and high power density (0.35 mW h cm−3 at 300 mW cm−3), respectively. Additionally, a liquid crystal display was driven by the two serial and two parallel connected MSCs for 35 s after charging for 3 s. [ABSTRACT FROM AUTHOR]