Synthesis and Characterization of Ru-MOFs on Microelectrode for Trace Mercury Detection †

Mercury ions (Hg [Formula: see text]) pollution in the water environment can cause serious harm to human health. Trace Hg [Formula: see text] detection is of vital importance for environmental monitoring. Herein, we report a novel design of Ru-MOFs modified gold microelectrode for Hg [Formula: see text] determination. Ru-MOFs are synthesized directly by the cathodic method on gold microelectrode, with the covered area accurately controlled. Cathodic synthesized Ru-MOFs show good conductivity and are suitable to be used as the electrode surface material directly. The synergy of the pre-deposition process and the adsorption process of Ru-MOFs can effectively improves the performance of the sensor. The results show good linearity (R [Formula: see text] = 0.996) from 0.1 ppb to 5 ppb, with a high sensitivity of 0.583 [Formula: see text] A ppb [Formula: see text] mm [Formula: see text]. The limit of detection is found to be 0.08 ppb and the test process is within 6 min. Most importantly, the senor has a good anti-interference ability and the recoveries are satisfactory. This miniature electrochemical sensor has the potential for on-site detection of trace mercury in the field.