Electroanalytical sensing of Cd2+ based on metal–organic framework modified carbon paste electrode

[Display omitted] •The influence of an amino group of TMU-16-NH2 on the oxidation current of cadmium was investigated.•TMU-16-NH2 molecules owing to their amino groups, caused to increase the interaction between Cd2+ and the modified electrode surface.•Graphene was used in order to increase the surface of the modified electrode.•Mixing of graphene, TMU-16-NH2, carbon powder and mineral oil in one step led to a simple method for fabricating the sensor. This paper reports, for the first time, the fabrication and characterization of sensitive electrochemical sensor for the efficient detection of cadmium ion using metal organic framework (MOF). TMU-16-NH2 ([Zn2(NH2-BDC)2(4-bpdh)]·3DMF) a kind of metal organic frame works was used as a modifier. The interaction between cadmium and amine groups of TMU-16-NH2 are conditioned by dative attachment that caused Cd2+-N complexation by soft–soft interactions. To achieve the highest efficiency of the sensor, effective factors on analytical response such as pH, deposition potential and deposition time have been optimized. Under optimal experimental conditions, the oxidation current increased by the addition of cadmium in the sample and dynamic ranges obtained from 0.7 to 120 by differential pulse voltammetry (DPV). This method exhibited a lower limit of detection (LOD) of 0.2μgL−1 (S/N=3). The presented work demonstrates that the MOFs are effective materials to fabricate efficient electrochemical sensors for the easy and costly effective detection of cadmium ions in solutions.