A Co{P₄Mo₆}-based compound as an electrochemical sensor for highly sensitive detection of Cr(VI)

This study reports the synthesis of the {CoP₄Mo₆}-based compound LLXY-110 and its use as a high-performance electrocatalyst for the detection of ultra-rare Cr(VI). Relying on the synergistic cooperation of the {P₄Mo₆} cluster and the Co metal center, LLXY-110 demonstrated exceptional sensitivity (228.0 μA μM^-1) and an extremely low detection limit (9.2 ppt) at pH = 2, while maintaining stable performance over a wide pH range (pH = 0-5). This sensor demonstrated outstanding selectivity, stability and anti-interference ability. The actual verification was carried out with lake water containing Cr(VI), confirming the high accuracy and repeatability of this method and emphasizing its potential in environmental monitoring. This work has advanced the design of polyoxometalate-based electrochemical sensors for the detection of harmful pollutants under actual conditions.