A highly conductive and mesoporous samarium metal–organic nanorods for the trace-level electrochemical detection of toxic mercury ions in lake water

Abstract

The research outlines an ultrasensitive electrochemical detection of trace-level mercury using an Sm-BTC metal–organic framework. The Sm-BTC metal–organic framework was synthesized via a simple solvothermal method and characterized through various analytical techniques. The FTIR spectrum shows two important peaks at 732 cm−1 and 554 cm−1 which confirms the formation of the metal–organic framework and the surface morphology of the material was characterized through SEM analysis which shows the multilayered nanorod structure. The mesoporous nature of the material was confirmed by BET analysis. The electrochemical studies including Cyclic voltammetry and Square wave voltammetry prove the Sm-BTC modified glassy carbon electrode has shown remarkable sensitivity and selectivity towards the sensing of mercury ions than the unmodified bare glassy carbon electrode. The Sm-BTC modified GCE with the optimized electrochemical parameters for the sensing of mercury ions confirms that the sensor has a very low LOD (Limit of Detection) of 10 nM. It is lower than the guideline concentration of mercury (30 nM) by the World Health Organization and the linear range is 0.01 µM to 50 µM with a correlation coefficient of 0.9926. Further, this sensor has shown an excellent sensitivity of 91.760 µA µM−1 cm−2. The real sample analysis of the current study proves the reported sensor is effective for the determination of Hg2+ ions as it shows a very good recovery percentage.