Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of the Education Ministry, Shanxi University, Taiyuan, Shanxi 030006, P. R. China.
Department of Chemistry, University of North Texas CHEM 305D, 1508 W Mulberry St, Denton, Texas 76201, United States.
ACS Appl Mater Interfaces. 2022 Jun 22;14(24):28280-28288. doi: 10.1021/acsami.2c04645. Epub 2022 Jun 10.
Excessive phosphate poses a serious ecological and human health risk, and thereby, monitoring its trace concentration is of great significance to environmental protection and human health. In this work, a zirconium-porphyrin framework (PCN-222) with excellent stability and unique luminescence properties was designed to modify the surface of the indium tin oxide electrode, which was first used as a photoelectrochemical (PEC) probe for phosphate detection. The PCN-222-modified PEC probe demonstrated an excellent selectivity and stability and indicated a linear response to phosphate in the range of 0-10 nM with a limit of detection (LOD) as low as 1.964 nM. To the best of our knowledge, this is the phosphate probe with the lowest LOD, and this is also the first signal-on PEC probe toward phosphate based on PCN-222. More importantly, the PEC probe can be validated for the good applicability of trace phosphate detection in real water samples, indicating a good application prospect. Finally, a series of electrochemical and spectroscopic studies have proved that phosphate can bind to the indium tin oxide (ITO)/PCN-222 electrode, which shortens the distance of the space charge region while reducing the bandwidth and thus facilitates the transfer of photogenerated electrons across the energy band barrier to reduce O in the electrolyte, producing an enhanced cathodic photocurrent signal. The proposed strategy of the highly sensitive PEC probe provides a promising platform for more effective label-free phosphate monitoring in the environment and organisms.
过量的磷酸盐会对生态和人类健康造成严重威胁，因此，监测其痕量浓度对于环境保护和人类健康具有重要意义。在这项工作中，设计了一种具有优异稳定性和独特发光性能的锆卟啉骨架（PCN-222）来修饰氧化铟锡电极的表面，该电极首次被用作光电化学（PEC）探针用于检测磷酸盐。PCN-222 修饰的 PEC 探针表现出优异的选择性和稳定性，对磷酸盐在 0-10 nM 范围内表现出线性响应，检测限（LOD）低至 1.964 nM。据我们所知，这是具有最低 LOD 的磷酸盐探针，也是基于 PCN-222 的首个用于检测磷酸盐的信号开启型 PEC 探针。更重要的是，该 PEC 探针可用于验证痕量磷酸盐在实际水样中的良好适用性，表明其具有良好的应用前景。最后，一系列电化学和光谱研究证明，磷酸盐可以与氧化铟锡（ITO）/PCN-222 电极结合，从而缩短空间电荷区的距离，同时减小能带宽度，从而促进光生电子在能带势垒上的转移，减少电解质中的 O，产生增强的阴极光电流信号。所提出的高灵敏度 PEC 探针策略为在环境和生物体中更有效地进行无标记磷酸盐监测提供了一个有前景的平台。
