Bioanalytical Chemistry-Aquaculture and Wildlife Management, Department of Agri-food, Environment, and Animal Sciences (Di4A), University of Udine, Via Sondrio 2/A, Udine, Italy.
Chemistry Department, Molecular Sciences Research Hub, Imperial College London, London, UK.
Mikrochim Acta. 2023 Mar 15;190(4):135. doi: 10.1007/s00604-023-05679-1.
The development of a highly sensitive electrochemical sensor (E-sensor) is described based on stand-alone plastic electrodes (PE) for phosphate detection, being an essential nutrient in the marine environment. The detection mechanism is based on the chemical affinity between polyoxomolybdate anions (POM) and orthophosphate to form an electroactive phosphomolybdate complex. The custom-made E-sensor was formulated with an organic octamolybdate derivative (TBAMoO) incorporated with periodic mesoporous organosilica (PMO) to obtain a significant improvement in the analytical performances of phosphate determination. This POM@PMO combination was found to be advantageous in the determination of low concentrations of phosphate in standard solutions ranging from 1 to 500 nM, using square wave voltammetry as the detection technique. This sensitivity enhancement can be attributed to the effect of hydrophobic PMO in loading more POM moieties, owing to its highly porous structure and charged shell. Consequently, the POM@PMO-PE sensor achieved a competitive sensitivity of 4.43 ± 0.14 μA.nM.cm and a limit of detection of 0.16 nM with good selectivity against silicates. Finally, seawater and treated wastewater samples have been tested to validate the sensor response in comparison to the official method of phosphate determination.
本文描述了一种基于独立式塑料电极（PE）的高灵敏度电化学传感器（E-sensor）的开发，用于检测磷酸盐，磷酸盐是海洋环境中的一种重要营养物质。检测机制基于多聚钼酸盐阴离子（POM）与正磷酸盐之间的化学亲和力，形成电活性的磷钼酸盐络合物。定制的 E-sensor 由有机八钼酸盐衍生物（TBAMoO）与周期性介孔有机硅（PMO）结合而成，以获得对磷酸盐测定的分析性能的显著改善。事实证明，这种 POM@PMO 组合在使用方波伏安法作为检测技术的情况下，对于测定标准溶液中 1 至 500 nM 范围内的低浓度磷酸盐具有优势。这种灵敏度增强可归因于高度多孔结构和带电壳的疏水性 PMO 在负载更多 POM 部分方面的作用。因此，POM@PMO-PE 传感器实现了 4.43 ± 0.14 μA.nM.cm 的竞争灵敏度和 0.16 nM 的检测限，对硅酸盐具有良好的选择性。最后，测试了海水和处理后的废水样品，以验证传感器响应与磷酸盐测定的官方方法相比的有效性。
