In this work, three kinds of bimetallic Prussian blue analogues (PBAs), i.e. K_xNi [Fe(CN)₆]·nH₂O (NiFe-PBA), K_xCo [Fe(CN)₆]·nH₂O (CoFe-PBA), and K_xMn [Fe(CN)₆]·nH₂O (MnFe-PBA), were synthesized by a simple precipitation method under identical conditions. Their chemical compositions, structures, morphologies, valences of transition metals, and electrochemical sensing performances for 2-nitrophenol (2-NP) are examined in details. It is found that all the prepared PBAs hold face-centered-cubic structures with near perfect cube morphologies for NiFe-PBA and CoFe-PBA and truncated cube morphology for MnFe-PBA. For the electrochemical detection of 2-NP, a wide detection range of 1.0–700.0 μM was obtained at all PBAs modified electrodes together with the sensitivities of 443.3, 368.0, and 339.0 μA cm⁻² mM⁻¹ and detection limits of 0.28, 0.46, and 0.59 μM achieved at NiFe-PBA, CoFe-PBA, and MnFe-PBA modified electrodes, respectively. The superiority in electrochemical sensing performance of NiFe-PBA to CoFe-PBA and MnFe-PBA may stem from its higher conductivity, lager electroactive surface area, and better intrinsic catalytic property of the transition metal in its framework. Furthermore, the constructed NiFe-PBA-based sensor displays good repeatability, long-term stability, and high selectivity together with desirable recoveries (97.8–103.9%) for the assay of 2-NP in water samples. The present work is the first report on the PBAs-based electrochemical sensors for 2-NP detection, which may promise a future of PBAs or PBAs-based materials for sensing applications.

在这项工作中，三种双金属普鲁士蓝类似物（PBA），即K _x Ni [Fe（CN）₆ ]·nH ₂ O（NiFe-PBA），K _x Co [Fe（CN）₆ ]·nH ₂ O （CoFe-PBA）和K _x Mn [Fe（CN）₆ ]·nH ₂O（MnFe-PBA），是在相同条件下通过简单的沉淀法合成的。详细检查了它们的化学组成，结构，形态，过渡金属的化合价以及对2-硝基苯酚（2-NP）的电化学传感性能。发现所有制备的PBA都具有面心立方结构，其中NiFe-PBA和CoFe-PBA具有近乎完美的立方形态，而MnFe-PBA具有截短的立方形态。对于2-NP的电化学检测，在所有PBA修饰电极上获得了1.0-700.0μM的宽检测范围，灵敏度为443.3、368.0和339.0μAcm ^-2  mM ^-1NiFe-PBA，CoFe-PBA和MnFe-PBA修饰电极的检测极限分别为0.28、0.46和0.59μM。NiFe-PBA的电化学传感性能优于CoFe-PBA和MnFe-PBA，这可能是由于其框架中过渡金属的更高电导率，更大的电活性表面积以及更好的固有催化性能。此外，构造的基于NiFe-PBA的传感器显示出良好的重复性，长期稳定性和高选择性，以及用于水样中2-NP测定的理想回收率（97.8-103.9％）。当前的工作是有关用于2-NP检测的基于PBAs的电化学传感器的第一份报告，这可能预示了用于传感应用的PBA或基于PBAs的材料的未来。