Simple electrochemical sensing for mercury ions in dairy product using optimal Cu-based metal-organic frameworks as signal reporting.

A convenient sensor is developed for electrochemical assay of Hg in dairy product using the optimal Cu-based metal-organic frameworks (Cu-MOFs) as signal reporting. Benefiting from specific recognition between Hg and thymine (T)-rich DNA strands, the interferences of milk matrices are effectively eliminated, thereby greatly improving the accuracy of test results. Moreover, the suitable Cu-MOFs offer an efficient carrier for probe design, and the contained Cu ions could be directly detected to output electrochemical signal of Hg presence without labor- or time-intensive operations. Compared with previous methods, this sensor substantially simplifies the process of electrochemical measurement and facilitates highly sensitive, selective and rapid analysis of Hg with detection limit of 4.8 fM, offering a valuable means for monitoring dairy product contamination with Hg.