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A sensitive hydrazine electrochemical sensor based on Zinc oxide nano-wires (ZnO NWs) synthesized from low temperature hydrothermal method has been fabricated using an add-on technique. The morphology, crystalline structures, and composition of synthesized ZnONWswere characterized by scanning electron microscopy,X-ray powder diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy. The batch-made ZnO NWs were used as electrocatalytic material andmodified on the gold electrode surface through a printing-like method via Nafion to obtain Nafion/ZnO NWs/Au hydrazine electrochemical sensor. To optimize performance, the effect of the ZnO modified quantity on sensitivity was evaluated by cyclic voltammetry, electrochemical impedance spectroscopic, and single-potential amperometry techniques. The results show that the optimum ZnO NWs modified quantity is about 170 µg ⋅ cm-2. The optimized Nafion/ZnO NWs/Au hydrazine electrochemical sensor has a high sensitivity of 3.8 µA⋅µM-1 ⋅ cm-2, a short response time of 3 s, and a very low detection limit of 0.0144 µMwith a linear hydrazine concentration response range from 3.0 to 562 µM. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study which examined the prevalence of social isolation from religious group members and close friends and the association with DSM-IV anxiety, mood and substance use disorders. The study showed that Americans lacked close friends or religious group members that they frequently contact in their social network. It concludes that social isolation is common in the U.S. and associated with mental health problems.