Sensitive Detection of Cadmium Using Amine-Functionalized Fe-MOF by Anodic Stripping Voltammetry

Abstract

The present work reports the application of an iron-based metal–organic framework (MOF), i.e., NH2-MIL-53(Fe), modified glassy carbon electrode (GCE) for the selective and simple electrochemical detection of trace levels of cadmium using square-wave anodic stripping voltammetry (SWASV). The NH2-MIL-53(Fe) MOF was coated on a GCE to fabricate the above heavy metal sensor. The SWASV response of the above-prepared NH2-MIL-53(Fe)/GCE sensor was optimized against various factors such as pH, deposition potential, and deposition time. The performance of the sensor was further evaluated for different concentrations of cadmium ions (Cd2+). The sensor showed a response in a wide linear concentration range of 44 nM–2.22 μM. Based on the above response, the limit of detection and the limit of quantification have been estimated to be 0.03 and 0.09 μM, respectively. The developed sensor also displayed selectivity toward Cd2+ metal ions even in the co-presence of several other commonly associated metal ions. In addition, the sensor exhibited a reproducible and stable response. The practical significance of the sensor was demonstrated by analyzing cadmium in some spiked water samples.