Carbon nanotube-based extraction and electrochemical detection of heavy metals

Abstract

In this mini review, recent trends and challenges in developing carbon nanotube-based extraction and electrochemical detection of heavy metals in water are reviewed. Carbon nanotubes (CNT) have electrical, mechanical, chemical, and structural properties superior to those of conventional materials, for example graphite and activated carbon. CNT-based procedures are also more efficient than traditional techniques and methods, for example liquid-liquid extraction, atomicabsorption spectroscopy, flame photometry, and inductively coupled plasma, because they can enable rapid, sensitive, simple, and low-cost on-site detection. Different forms of CNT, including as-grown, oxidised, and functionalised CNT, can be well suited to metal adsorption. The measurement procedure relies on adsorbing the metal on the CNT surface after reasonable contact time, either by applying an electrical potential or under open-circuit conditions, and subsequent quantification. Different types of CNT-based electrode, including composite, paste, and binderfree, can be fabricated and used for metal detection. Application of CNT and their novel properties to the adsorption and detection of heavy metals is discussed in detail.

Advances in the Development of Innovative Sensor Platforms for Field Analysis

“…On the other side, carbon nanomaterials can also ensure excellent electron transferability. In this way, the lowest limits of detection reach 0.04 ppb for Pb 2+ , 0.02 ppb for Cd 2+ , and 15 ppb for Cu 2+ [29,30]; typical curves on the evaluation of heavy metal ions concentrations through nanostructured carbon black are reported in Figure 3a, based on differential pulse anodic stripping voltammetry (DP-ASV) [31]. In addition, the reduction of electrode size obviates problems such as a high potential for analyte deposition, high stripping potential of the analyte, and low selectivity.…”

A review on detection of heavy metal ions in water – An electrochemical approach

“…Although CNTs have high electrical conductivity, fast electron transfer rates, and excellent strength, etc., [133][134][135][136][137] they suffer from high background current and absence of reactive functional group for the interaction with heavy metal ions. This can be overcome by sealing the side-walls of CNT with epoxy and this has minimized the current leakage [138].…”

Synthesis and Applications of Organic-Based Fluorescent Carbon Dots: Technical Review

“…Synthesis and Applications of Organic-Based Fluorescent Carbon Dots: Technical Review DOI: http://dx.doi.org/10.5772/intechopen.94511 Because of their excellent properties; carbon material performs concurrently as adsorbent and a transducing-agent [138][139][140][141].…”