Comparative study of graphene nanosheet- and multiwall carbon nanotube-based electrochemical sensor for the sensitive detection of cadmium

• A nanocomposite based on nanographene and Nafion is used as a platform for cadmium detection.
• The performance of the nanographene-based sensor was compared with that of MWCNT.
• It indicated that the nanographene-based sensor possessed significant advantages over MWCNT.
• The nanographene-based sensor proved to be a reliable tool for rapid detection of cadmium.

A novel nanocomposite was obtained through the controlled surface modification of graphene nanosheets (nanographene) with Nafion by ultrasonic oscillation. The composite was used as an ultrasensitive platform for the detection of cadmium ions (Cd2+) by differential pulse anodic stripping voltammetry (DPASV) analysis. The performance of the nanographene-based sensor was systematically compared with that of a multiwall carbon nanotube (MWCNT)-modified sensor. The results indicate that the nanographene-based sensor exhibits significant advantages over the MWCNT-based sensor in terms of repeatability, sensitivity and limit of detection (LOD). The nanographene-based sensor displayed superior analytical performance over a linear range of Cd2+ concentrations from 0.25 μg L−1 to 5 μg L−1, with a LOD of 3.5 ng L−1. This sensor was also used to systematically screen for 6 types of chemicals, including sodium salts, magnesium salts and zinc salts. It was observed that the sensor could successfully differentiate cadmium ions from interferents (magnesium salts, zinc salts, etc.). The nanographene-based sensor was also demonstrated to be a promising and reliable tool for the rapid detection of cadmium existing in tap water and for the rapid on-site analysis of critical pollution levels of cadmium.

Schematic diagram of nanographene-based sensor detection of cadmium ions by stripping analysis.Figure optionsDownload as PowerPoint slide