Nanomaterials-based electrochemical detection of heavy metals in water: Current status, challenges and future direction

The existence of heavy metals in the natural waters poses serious threats to human health and the environment. Therefore, development of detection methods for monitoring of these heavy metals is crucial. The nanomaterial-based electrochemical sensors have been extensively employed for heavy metal ions detection. The fabricated electrodes offer several advantages and improved performance due to the design of electrode surface at the nanoscale that render increased catalytic activity and conductivity, active large surface area and fast electrode kinetics. Moreover, integration of electrochemical devices in automatic fluidic structures has also been used for a wide range of heavy metals monitoring. This review will provide a detailed account of recent progress in the development of nanomaterial-based electrochemical sensors for the detection of heavy metals in real water samples from 2013 onwards. The design of these sensors is based on the deployment of nanoparticles-modified electrodes, microelectrode and nanoelectrode arrays, and microfluidic electrochemical devices.