Phosphate is an important analyte to monitor in various water bodies. Cobalt based sensors are attractive for this application as they are solid-state, have a quick response time, are easy to fabricate and can perform reagent-less measurements. However, these sensors have lower sensitivity, limited dynamic range and require a chemical conditioning in a standard solution before measurement. In this study, an in situ anodic current pretreatment method in sample solution itself is used to enhance the sensitivity of the sensor and alleviate the need of chemical conditioning before measurement. With electrical pretreatment, the sensor exhibited a linear range from 10⁻⁶ M to 10⁻³ M with a sensitivity of −91.4 mV/decade of change in dihydrogen phosphate concentration. No significant interference was detected with common interfering anions that are typically present in field water samples such as nitrate, sulfate and chloride. Finally, the sensor was also responsive when tested real water samples such as tap water, lake water and creek water spiked with phosphate.

磷酸盐是各种水体中需要监测的重要分析物。钴基传感器对这种应用很有吸引力，因为它们是固态的，响应时间快，易于制造并且可以进行无试剂测量。然而，这些传感器的灵敏度较低，动态范围有限，并且在测量前需要在标准溶液中进行化学调节。在这项研究中，在样品溶液本身中使用原位阳极电流预处理方法来提高传感器的灵敏度并减轻测量前化学调节的需要。通过电预处理，传感器表现出从 10 ^-6 M 到 10 ^-3的线性范围M 具有 -91.4 mV/十年磷酸二氢浓度变化的灵敏度。现场水样中通常存在的常见干扰阴离子（如硝酸盐、硫酸盐和氯化物）未检测到显着干扰。最后，该传感器在测试真实水样（例如自来水、湖水和掺有磷酸盐的小溪水）时也能做出响应。