A new sensitive colorimetric sensor was designed to investigate the presence of Hg²⁺ in aqueous solution by using Fe₃O₄ NP impregnated on carbon nanocomposite(MPC) synthesized from MIL88 A which possess an excellent peroxidase mimicking activity that brings oxidation of 3, 3’, 5, 5’‐ tetramethylbenzidine (TMB) under the influence of hydrogen peroxide (H₂O₂) to produce blue colour in the solution. The solution was decolorized by the addition of Glutathione (GSH) which restores the TMB radical cations and ceased the oxidation reaction. Addition ofHg²⁺ ions to the solution bring back a strong blue colour due to the strong affinity of Hg ²⁺ with the thiol groups of GSH which promote the oxidation of TMB in the solution. Based on these strategies, we have developed a sensitive andselective colorimetric sensor for the determination of Hg (II) in aqueous solution with the detection limit value of 236 pM and a linear relationship of R²=0.994. The proposed mechanism was successfully implemented for the detection of mercury in real water samples for environmental applications.

中文翻译：

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磁性多孔碳（MPC）在水介质中Hg（II）离子的比色传感中增强的过氧化物酶模拟活性

设计了一种新的灵敏比色传感器，通过使用浸渍在MIL88 A合成的碳纳米复合物（MPC）上的Fe ₃ O ₄ NP来研究水溶液中Hg ²⁺的存在，该化合物具有出色的过氧化物酶模拟活性，可氧化3、3 '，5，5'-四甲基联苯胺（TMB）在过氧化氢（H ₂ O ₂）的影响下在溶液中产生蓝色。通过添加谷胱甘肽（GSH）使溶液脱色，谷胱甘肽（GSH）可恢复TMB自由基阳离子并终止氧化反应。由于Hg ²⁺具有很强的亲和力，因此向溶液中添加Hg ²⁺离子会带来强烈的蓝色具有GSH的巯基，可促进溶液中TMB的氧化。基于这些策略，我们开发了一种灵敏且选择性的比色传感器，用于检测水溶液中的Hg（II），检测极限值为236 pM，线性关系为R ² = 0.994。所提议的机制已成功实施，用于检测环境应用中的真实水样中的汞。