Baby Jeena N, Sriram Balasubramanian, Wang Sea-Fue, George Mary, Govindasamy Mani, Benadict Joseph Xavier
Department of Chemistry, Stella Maris College, Affiliated to the University of Madras, Chennai-600 086, Tamil Nadu, India.
Nanoscale. 2020 Oct 14;12(38):19719-19731. doi: 10.1039/d0nr05533f. Epub 2020 Sep 23.
Potentially hazardous chemical contaminants endanger the environment and human well-being, challenging scientists and policy makers to develop holistic alternative approaches for remediation. The addition or accumulation of these chemicals can have a series of far-reaching consequences and have direct and indirect effects at multiple levels of ecological organization. Therefore, the development of a sensitive tool for the comprehensive evaluation of chemical concentrations is highly relevant. Herein, we thus report the simultaneous electrochemical detection of highly toxic hydroquinone (HQ), Hg, and nitrite (NO) compounds using nanostructured metal molybdate (M = Mg, Fe and Mn) catalysts. These functional nanomaterials are synthesized using a deep eutectic solvent (DES) modified hydrothermal method that provides sustainable aspects and energy efficient synthesis strategies. Choline chloride (ChCl)-urea DES used in this study exhibits an all-in-one behaviour by simultaneously acting as a template, reducing agent, and homogeneous means for stabilizing metal ions. This stimulates the fabrication of hierarchical structures of metal molybdates with high surface activities that cause their remarkable properties with minimal waste generation. The structural, morphological, catalytic, and electrochemical capacities of the as-synthesized MgMoO, Fe(MoO), and MnMoO materials are explored through various techniques and comparatively, MnMoO presents superior characterization features such as a reduced particle size, increased surface area and hierarchical architectures. Owing to the exceptional physicochemical attributes, the MnMoO modified glassy carbon electrode (GCE) demonstrates superior electrochemical activities towards the individual and simultaneous detection of HQ, Hg, and NO. Well-defined and separate peaks are observed for the simultaneous detection of HQ, Hg, and NO which is influenced by the binding energies of these pollutants. Furthermore, the modified electrode exhibits a high sensitivity of 23.8, 17.7 and 10.2 μA μM cm with a limit of detection (LOD) of 0.026, 0.05, and 0.01 μM for HQ, Hg, and NO respectively under ideal conditions. Also, the reproducibility and anti-interference ability reinforce the application potential of the MnMoO modified electrode for the simultaneous electrochemical detection of HQ, Hg, and NO in real samples with better recoveries, thus assessing the effect of these hazardous chemicals on humanity.
潜在危险的化学污染物危及环境和人类福祉，这促使科学家和政策制定者开发全面的替代修复方法。这些化学物质的添加或积累会产生一系列影响深远的后果，并在生态组织的多个层面产生直接和间接影响。因此，开发一种用于综合评估化学物质浓度的灵敏工具具有高度相关性。在此，我们报告了使用纳米结构金属钼酸盐（M = Mg、Fe和Mn）催化剂同时电化学检测剧毒对苯二酚（HQ）、汞和亚硝酸盐（NO）化合物。这些功能纳米材料采用深共熔溶剂（DES）改性水热法合成，该方法具有可持续性且提供了节能的合成策略。本研究中使用的氯化胆碱（ChCl）-尿素DES具有一体化作用，同时充当模板、还原剂和稳定金属离子的均相介质。这促进了具有高表面活性的金属钼酸盐分级结构的制备，这些结构具有显著特性且产生的废物最少。通过各种技术探索了合成的MgMoO、Fe(MoO)和MnMoO材料的结构、形态、催化和电化学性能，相比之下，MnMoO具有优异的表征特征，如粒径减小、表面积增加和分级结构。由于其特殊的物理化学属性，MnMoO修饰玻碳电极（GCE）对HQ、汞和NO的单独及同时检测表现出优异的电化学活性。同时检测HQ、汞和NO时观察到清晰且分离的峰，这受到这些污染物结合能的影响。此外，在理想条件下，修饰电极对HQ、汞和NO的检测限（LOD）分别为0.026、0.05和0.01 μM，灵敏度分别为23.8、17.7和10.2 μA μM⁻¹ cm⁻²。而且，该修饰电极的重现性和抗干扰能力增强了其在实际样品中同时电化学检测HQ、汞和NO的应用潜力，回收率更高，从而评估这些有害化学物质对人类的影响。
